I'm totally lost as to Rogue's current power state. Its been mentioned she no longer has Ms Marvel's powers, but she is often shown using them. You say she can control her powers now, and I'm sure you are right.
I used to love the character, but since the Siege Perilous she has had very little character at all - in my opinion. There have also been some very messy rewrites since.
For my money, Rogue is destined to end up back as the unkissable beauty that chimed so well with everything the Xmen were about back in the 1980s. For me, Rogue as an Avengers would be like Cyclops, Wolverine (I'm over it) or Nightcrawler becoming Avengers. They are just too Xy.
When you say she would fit perfectly in the Avengers, I guess you are saying this because she is a convert to good. Converts work well as Avengers. Can't argue with that.
Her normal state is be non-powered, but she can absorb and (usually does so) the powers of others. Whole or just fractions.
She lost Ms. Marvels powers a long time ago, but she did reabsorb them along with her EP during the last fight of the two. Temporary, I am afraid.