How much shoulder turn is really needed?

[buddha]

Being an older player and not flexible I don't come anywhere near to a 90 degree turn with the shoulders.

How important is it to get a 90 degree turn?

I remember there was a senior tour player that had hardly a shoulder turn at all and he did quite well.

Any players with little shoulder turn but had power and how did they achieve it?

[mvmac]

Well you're a 3 handicap so the amount of shoulder turn you're getting is probably not as bad as you think.  How much is needed?  I would say it's rare to see a good player with less than 80.  I bet you can increase your turn though, make sure to flare your right foot out and allow the rear knee to decrease in flex http://thesandtrap.com/t/55080/myth-of-maintaining-address-flexion-in-the-rear-knee