So far I have used the medal system to award a single medal to a single member of my alliance on both accounts. In both instances I felt they were a really wonderful way to recognize uniquely valuable members. They aren't cheap, so there will never be a lot of people running around with medals but they play a role in our alliance.
The Alliance Prestige Pool is a great idea, imnsho. Donated Prestige can make a significant contribution to the alliance. Again, it's real money, so I won't be donating a ton of it, but it could really be handy sometime to research a move in a member's town faster or boost a member's defenses for example. The "Hot Seat" rank is an interesting idea.
As for other's donations, that is their business. TLR has not and will not solicit donations. I expect that is the way it will play out in most alliances. Any alliance that uses the pool recklessly or "requires" donations won't get or keep members.