i have had an issue with casting the club at the top in the past...still have it from time to time i guess.....i just changed my grip from overlap to interlock....i believe this has limited my casting a bit but now i drive and hit shots that go right from time to time......but not too much with irons but drastic on woods

QUESTIONS..........
1. am i swinging with my arms too much?
2. should i be moving a little more with intiating a bump with my lower body to create some lag?

side note: i do at times get into a nice rythms and trap the ball beautifully.....but lately my drives have been awful....to the point where on some local course i can get away with using a 3 iron off the tee for 225-230....but i know on longer courses i will need my driver