True on those accounts. I wonder if he did and if he would at times assume the Gandalf appearance once in a while.
Saruman went evil, Radgast fell by the wayside, so to speak, since he got to caught up in caring for animals it seems. As for the 2 blue wizards I read that early on Tolkein said they fell to serving Sauron, but I read later on he was thinking maybe they didn't and stayed in the east to try to talk folks into rebelling against Sauron, so not sure about them.