Well, he was 10 times better than DeRita, but Curly was 10 times better than him.
You know a comedian that WOULD have been Stoogeworthy after Shemp?
Buddy Hacket. Imagine! I have read that he was heavily considered by the studio, but was not chosen. I cannot substantiate this, but I have read or heard it before. I gotta figure that he was in his 20's in 1950....a little to young for the now near geezer Moe and Larry.
The "Hacket as a Stooge" idea was apparently a story Buddy Hackett told once. He also stated that he turned down the offer to become a Stooge because of the violence. From what Jules White said, this story was probably a lie.
I also heard another story that Moe was considering Mantan Moreland as a Stooge. I'm not sure if this was true or not.
After Besser left, Larry considered Paul "Mousie" Garner as a replacement; the boys tried him out, but had to let him go. Moe later stated in an interview that Garner was "completely unacceptable".
As for the haircuts in the Besser shorts, I think this had to do with how times had been changing in the comedy field during this period. After the 1930s, very few newer comics dressed like clowns. Instead, they dressed like normal people. This included Abbott and Costello, Bob Hope, and (in his earlier films) Red Skelton. Besser probably went along with this idea.