Regarding Bay Keep, I don't hate it but its not one of my favs.
I don't have any cav suggestions for you but there are a few things I do not like. I think there should be a little more cover for initial spawn area. Its still too open for projectiles as soon as you spawn. I also do not like the walk along the wall. Everyone is wide open for arrows for what seems like forever before the fight in the keep. I would like to see another way to get to the other side of the spawn. There are 2-3 broken bridges in the middle. Maybe something could get connected there. That would provide a third spot to fight up front. As it is, all fighting happens 1) inside the keep after a long walk, 2)a few on the grass, then once someone wins the keep, 3)at enemy spawn to get the stragglers. So there's lots of fighting in small spaces or catwalks. Neither of which are that fun.
I also would like a barrier on the back side of the keep, where the wooden walkway is located. Its easy to fall, survive and your only way back is to walk all the way around the map to the grass area. Some people don't realize you can even get back and will suicide. Either a barrier to prevent the fall or make the fall higher to ensure a death.
Edit for above post: Someone should change the MOTD on the servers into big bold letters notifying them of the map vote thread. I mention it in-game every time someone bitches and moans about a map but doesn't seem to make much difference.