Vanilla Map: I agree that if we go to 1.13 for rev 23, we should have a water-focused map to play with all the new features. I'm fine with vanilla map, maybe a watery one?
Map: Smaller map please? A smaller map means towns will be closer together, which encourages exploring and ground level rails. In the last several revs, I don't visit other towns much because it means a commitment in time to get there. Since much of the travel time is spent on underground rails, it's boring to watch too. I miss older revs where you could wander accidentally from one town to another because they were so close. And I miss above ground rails where you could see all kinds of amazing builds as you rode by.
Elytra: If maps are going to continue to be so big, we should make elytra easier to get. Make it so casual players can buy them with emeralds or diamonds. That way, everyone can fly around and make that the main means of transportation. I never use elytra because I'm too clumsy and would just lose a valuable item that's very hard to obtain. If elytra could be purchased after several hours of mining or farming, sure, I would use them to get around.
Nether Portals: I have enjoyed both the staged release of portals and the all-at-once release of portals. I don't have a preference.
Guilds: I think they are absolutely charming. I don't participate enough in them, but I love seeing people working toward them. I appreciate the work the admins put into them.