I'll be really careful to not take that groove down too far.   That was one reason I wanted some pro advice on this. 

Thats a good idea with the string, I may try that on the next one.  The bow is second or third hand, so I'm not sure what it originally came with, but I suspect it had a smaller diameter.  I can see why the person before me went to a thick string though, its a bit of a beast, and a slowly fraying string is nerve wracking, lol.