Maybe I will try to look at this in more details in future as now i am kind of bored and spending unusually large time at this forum. It would help if you post also your target location.

But here are just some quick thoughts about buildings:

You need Warehouse to have SoV researched, you need Storehouse to make Warehouse (storehouse can be destroyed later but why would you do it) and you need Brewery to make beer... that's clear.

You also need Marketplace to be able to deliver created beer somewhere.

You don't really need Vault.

You also need Library at max level to be able to research all needed things and mainly SoV needs research points as upkeep. So you should also make Statue discovery because if there are a lot of beer bonuses around, research points will be your beer production speed limitation.

You will also need to make at least minimal army (with commander) and so barracks so that you can claim SoV.

Architect office is one of my first buildings I focus on as it makes final goal reached faster (unless you are going to buy prestige and speed up builds I recommend this building)

And you need Consulate for diplomats for beer and statue discovery.

You can't have multiple mills, carpentry and co. but you can have multiple geomancers. Many people including me have 2 geomancers buildings to get higher food output. You need to calculate if you would need that, depends on how many beer SoV you can have.

Especially without any big army you can have lower tax and so big resource outputs.

Towns are not attacked by NPC currently.

For trader you need Merchant's guild and to sell things at Hub you need also Trade Office.

I doubt that your beer production will require more basic resources then you can produce.

5 resource plots at lvl 20: 12690 ... with 40%: 17766

3 resource plots at lvl 20:  7614 ... with 40%: 10659

those numbers are for 25% tax

my lvl 20 brewery making 15 beer p/h needs per hour only: 150 wood, 75 clay, 75 iron, 300 food, 15 gold

As you can see one town can easily make thousands resources every hour and so 150 wood can't really be any issue even if you would manage to get +300% on beer production.

I would not split "trading" part of town to another town because you will maybe anyway need some more not beer related buildings just to increase your population to optimal size. Optimal size depends on SoV around you...

1. If you have some plots available at th end, that it seems so, I would recommend you to have barracks and a small army.

2. There are no tradeoffs with geomancy spells, but you can only have 1 casted. The most common is to upgrade food production.

3. These bonuses for multiple buildings are not present in all buildings, but the ones that consume resources. And yes, many people uses them. A geomancy building could help to improve the percentage by which your production is increased by the spell.

4. It is good to have 1 or several traders, but now i think it is really too early. And you don't need any trader to sell or buy basic resources (beer included). However, this may change in the near future.

What I would advise if you want to build a city like this is that you first upgrade the basic resource production (wood, clay, iron, stone and food) to the maximum (I know it is boring!). Then use mills or other building to upgrade the basic production that you need. And start getting the sovereignity on the squares near you almost at the end, because they will also consume resources.

I guess that you may want/need to dedicate some squares near you to food production (and maybe also the geomancy spell (nature bounty) and maybe a geomancer building.

Ah, think that you will be raising taxes from time to time in your city, so that you can always get money, this would lower the production of your basic resources, that is why it is important that you upgrade them to the max.

Once it is maxed and the beer production at large scale is in place, you may think what to put on the empty squares you may have in the town. This will depend on what products you have excess (for example, if you have a lot of iron and good, you may also want to produce spears.

Finaly, think that we are now in the middle of a tournament, and with the danger of a war, so beer prices are quite high. Normaly they have been around 100 going up to 200 gold with the new crafting. I don't know if beer prices will remain tis high or they could decrease.

 Hope this could have helped a bit

TH

But for your beer SoV buildings you will need many basic resources as upkeep and so it will be issue and if there are more then 4 beer bonuses around you need to find optimal setup.

Brandmeister wrote: I suppose a Mage Tower and Consulate could stop thieves from stealing the beer, or saboteurs from ruining production. But if you're totally non-hostile, it seems that maybe you could get by with no attack forces?

Too risky.  If your settlement is near new players they might test their thieves, it's better when you have a protective ward.  Even T1 thieves can carry away beer.  

If you join an alliance you can end up in various kinds of hostilities between alliances not limited to diplo attacks.  If you don't join an alliance a good name for your settlement would be target.  And if you are inactive (not online) for days without a sitter, resulting in a flat pulse (=no change in pop) on Illy Stats, everybody and his dog will test your diplo defenses, and try to carry away what they can.

Brandmeister wrote: completing the Steamtastic Brewery mystery requires a ton of advanced spies, so I'll end up with a developed Consulate no matter what.

In theory you can demolish the consulate, in practice you want it at level 20 or maybe 19 for various reasons.  

Brandmeister wrote: I'm also willing to assume that any uber-player who wants to rob me is going to be successful simply by swamping the city with a legion of thieves.

As long as you have one defending thief attacks can fail.  Nothing can kill defending thieves in a city unless it is razed, captured, or runs out of gold to pay its diplos.  

Brandmeister wrote: I understand that Geomancy can upgrade your production of basic resources. This seems highly desirable, but are there tradeoffs to using this approach?

In isolated towns, out of reach of friendly geo towns, it's tricky.  You could spend more food for the geomancers than you get back from their nature's bounty spell.  Be careful when you reach  http://arcanum-illyria.com/wiki/Talk:Geomancers_Retreat" rel="nofollow - level 14.   In a cluster of towns only one needs geomancers, only two need blights, all want runes, and all want two or more future magic schools.  IOW, don't start the research for all three existing schools in all towns, and always get a mage tower to level 20 for the apocrypha research (5th school.)  Cast long-term geo spells on full moons with  additional mana.

Brandmeister wrote: Apparently you can have multiple Mills, Carpentrys, Foundries, Geomancer's Retreats and so forth to increase the various bonuses?

No, only where it's explicitly mentioned, as it's the case for the Geomancers' Retreat.

Brandmeister wrote: And that the bonuses are half as much for each successive building.  Does anyone use these, and are they worth it?

I have levels 15+11 in an isolated 5 food town for a 5*(15+11/2)=102.5% bonus.  In another town I got 18+16 for 130% before I understood that only 3 clay plots in a town are totally unsuited for geo or cav, let alone both. 

Fresh attempt 20+20 in another town with more clay planned for December.

Brandmeister wrote: Would it be smarter to not jump on this immediately, and instead later build a third city that is wholly trade-focused, adjacent to the brewing city?

The brewery is only one building, it can coexist with traders' office and merchant's guild.  Don't mix trading and crafting and gathering (=guilds excl. merchants) in one town.  Of course a guild town or a trade town can additionally craft something, but it's tricky.

Your main worry everywhere will be food, lots of food, more food, and above all food.  For that you need a 7 food square with, say, a 25% sov bonus, e.g., 11 food dolmen at level 5 for 11% plus normal 7+7=14  food sov for 14%.   And oops, there went some of your beer sov squares, they are needed for food.  

Maybe not. I don't have any numbers or calculations but I think in his special case food might be no issue. If only goal is beer production speed he might get it with small town for which 5 farms + mill could be enough.

He will have no military buildings, no other production buildings... theoretically also no horse and cows productions. He could achieve that max beer production with maybe only 10k pop.

Beer prices immediately started to rise: 123 was high near the end of tournament IV in January, after trade v2 in summer 200 was cheap.  Therefore I switched a sov square to a 2*(5+3)=16% beer bonus in my still growing 5 food capital.   Didn't work for me, it's again a 7% food bonus, the beer bonus also did not affect wine.  

In a town exclusively dedicated to beer it might be better to have +7% food with 2*(5+5)=20% beer bonus than +5% food with 2*(8+5)=26% beer bonus.  After all you can't do anything with the common grounds than breeding cows, and cows eat food.  For the paddock he could import horses and train them with a horse trainer, otherwise breeding horses also needs food.  

Doing nothing with common grounds and paddock can't be a good idea, unless it's an experiment, who brews the fastest steamtastic (ugh!) guiness for the Illy's book of records.  

Ultimately, one brewery active in most of your cities will produce more than enough beer to fill any military needs and leave you with a large surplus.  

This configuration would net you 8% more production bonus with the same resource consumption:

4x Sov IV @+8% =  128  (4800 Res/hr)

8x Sov IV @+5% =  160   (9600 Res/hr)

8x Sov III @5% =  120 (4800 Res/hr)

76.2 beer/hr  so you could probably make up the gold income selling off the beer.  

+1500 food/hour is needed which is, again, doable even with a 5 food city running ~12000 pop or less.