Upload & Sell: Off
This is just me. I would go bigger than the 36. The bigger the ball the better the grip.
Yes, but with a "traveler" tripod, the OP may want to be able to fold the legs back over the ballhead, and there can be clearance issues with larger ballheads (or a head with its knobs not optimally oriented). FWIW, the Markins Q3 (T or not) is the best ballhead in its size/weight class, and not too much more expensive than the PhotoClam equivalent.