The search function in Stash and in the Devotion screens are amazing and use them all the time. My suggestion is to add a search field in skill trees screen and in the personal inventory screens. For personal inventory I end up shoving my stuff in the Stash just so I can search for it there. This seems silly.
I also hate having to mouse over each skill to see what it does. Today I was leveling a character and I remembered that there was a skill that slowed down the targets walking speed that I had meant to get but it was one line in one of the 34 skills in my chosen class but I could not find it again.
I am sure this has been requested before but it would be a couple of nice things to have available to us.