Amature, it doesn't do any good for you to second guess everything, the only way you will know if something works is to try it and see for your self, being apprehensive about it does nothing but add fear into the equation.

You should know by now how to check your span, if it is too short, then have it lengthened to the proper fit and keep the pitches where they are and see if that helps before going more forward, make sure the span is right. Nobody on this site can tell you if your span is right without having you and your ball standing in the same room with us so we can see for ourselves. You need to find a ball driller you can trust, I have been telling you that for a long time now.

I was talking to my driller the other day and he said, "We could just stop messing around and I can put you where you should be at. I'm the one that's been calling the shots on my fit since any changes were made and he just let me do it although he does question quite a bit of it. He'd basically re-fit me from scratch. My guess, I'd be around 4 3/16(I'm at 4" now) give or take. The guys that fit me in Vegas had me at 4 1/4 and 4 1/8. Either way I'm thinking of just letting my Pro Shop do his thing for the span and modify the pitches accordingly.

The spans and the pitches are interconnected depending upon the severity of change in either the spans or the pitches. For instance, if you convert from 1/4" reverse pitch to 3/8" forward pitch in your thumb, it is likely that you would have to shorten your span.