My Evo was doing the same thing. I did factory reset and loaded my apps back up and it fixed those problems. I also left sense and am currently using adw launcher and I have more memory and the phone is fast as the day it came out. I have never rooted it before, its all stock. Hope that helps.
Thanks guys. The thing that sucks is I cant root because i have the 2.3.3 update. I got the Evo earlier this month from best buy and it came with 2.2 and i was thinking they would already have it rooted when i updated it at best buy. Hopefully they will come out with the root soon.