the best grip is the best grip that works for you. Where it goes wrong is when people try to use the wrong stroke with the wrong grip. As long as you are hitting up on the ball every time that BH should be just fine if it has always worked for you.
poly will not feel as good after playing with it, but you may or may not really care all that much. I personally would love to have a new set of poly every hit, but its just not financially viable and so I end up leaving it far longer than I should. Kirshbaum poly stings last a good long while...
what matters is the tension that the person wielding the racquet wants to play at. The number on the frame is merely what the company wants to print. If what you want to string at falls within the numbers on the frame, its fine. If it doesn't, its fine too.
Poly mains with either gut or multis is not very spin friendly, contrary to belief.
if you have gut and multi put the multi in the mains and the poly in the cross. Spin is good, but durability is pretty poor.
One often important overlooked fact in doubles is communication and player knowledge. Let the boys pair off into teams. They will tend to pair off into teams that will work together well, play well, communicate well together. Following this create a basic pre-determined ladder and have the teams...
4g is supposed to hold tension well. I have used it and I'm not really sure if it's the tension that stays well or if it's just that the string is so so stiff. probably a combination of the two really.
try natural gut. If you dont break strings it is a very cost effective setup since it stays playable pretty much until it breaks. decide if gut lasts long enough to warrent its higher cost.
prince synthetic gut/duraflex is good. Cheap to. (1/8) the cost of many guts)
the major cost of the will...