Question about the CFW Themes/ GBA Elimators(sp)

[discobob0100]

Hey guys its me again. I got 3 questions.

1) Lets say I upgrade my CFW to 3.90 M33, does that mean the CFW Themes i want to add to it MUST be 3.90 M33 or could i download a theme that is a lower version like 3.71 M33.

2) I wanted to add a GBA Elimator to my psp. But what i wanted to know is that do the Eliminators work on ANY CFW version? Or is there a particular version that i should have before I try it.

3) Also on my search on how to add the Elimator. I heard some people say its Illegal and other say its Legal. Which one is it???