[Q] Need advice about my new T800 topic

Hi all-

Looking for some advice on my new 16gb T800. I've been using it for a couple of weeks; generally happy but there's a few issues. I'm trying to decide if I should root, and then whether I should flash a new ROM. I've checked out the development sections, but since development is already pretty mature, maybe someone who's had this device for a bit might be able to give me advice. Here's the list of things I want:

Lollipop
Less bloat
Ability to install to SD card
Multi-user support
Multi-window for more apps, particularly Kindle (/rant: Why the heck is this feature so limited? It's half the reason I bought this tablet!)
Better MHL support (works fine on my TV but my monitor says "out of range")
disable capacitive buttons and put them on screen
PS3 controller support (over bluetooth)

So.... can anyone suggest what I should do? Simple root? ROM? Something else?

Thanks!