Could have sworn I saw a plugin for this a while ago, but I would like to see a plugin where you can keep certain chunks from unloading when players leave, that way people can actually move right when they respawn, and to improve the stargates for the same reason.
I don't think that would be a good idea, having extra chunks that do not need to be loaded could cause lag and stress the server to much.
Well, it depends on the situation. Unloading chunks also puts some stress on the server. If a chunk is loading/unloading very often, then it might be better to just leave it loaded. For example, the vanilla server leaves the spawn location always loaded, as it is used so often.
It also depends on how much memory you have, if you have loads of memory, then keeping chunks loaded shouldn't be an issue.
I have a server with a gig in it, but I will probably get 3 more gig sticks since they are only $12 each