Some good suggestions and are probably on Jasons to-do list like numbers 1 through 4.
Number 6 I agree with a NeoGeo platform but FBA (imho) doesn't deserve a platform since it really isn't one, its a multi system emulator just like Mame is. There is also nothing preventing you from making your own custom platform and creating / getting artwork for it.
Number 8 is already available, just go to Tools > Options > Images >Default Background and set it to Use Launchbox Default Background.
Number 9 is easily done with a file search filter like *.cue or *.sfc for example.
Number 10 is already there if you need to re do a game, just type in something close to what it is and it should populate the list with things closely matching as long as it is in the database.
Number 11 I do not agree with at all, it's nice having some options in BigBox mode without having to drop out to normal mode just to make a simple change.