To be honest with you the top few FE's have all those features you ask for (GameEx has just had a LEDWiz plugin added), Mala and Atomic FE have had LEDWiz support for a while.
I think GameEx, Mala and Atomic are all well documented. The easiest to setup is debatable, there is Atomic's Plug and Play which is probably very easy to use, and the Setup Wizard for GameEx makes setup pretty straight forward. I'm not sure how Mala is for setting up but I've seen a well written document that guides you through everything. Also not sure about MameWah but there was a setup program that made setup easier when I last checked it out.
There is no big following here for any one FE, in fact Atomic, MameWah and GameEx have their own forums which are the best place to ask questions for those FE's (although you will get answers here too). All developers are active too, so you can often get direct answers to bugs or requests from the big authors Tom, swindus, MinWah and Youki.
The Wiki is a good place to have a look at some comparisons, but I'm biased towards GameEx because that's what I use. Others will give you better advice on the others. Good luck finding a FE that suits your needs!
EDIT: As for rotation using a key, I know GameEx, Mala and Atomic all have this option. MameWah probably does too, but not sure.