Well, the problem I run into is finding the right shot for the shorter stuff. When I start messing with partial swings my timing gets way off, making it harder to hit the shot in the direction I want. Also, I do need to update my handicap. You can talk crap all you want but you aren't calling any bluff. Long tee shots aren't hard to do, many people can crush a drive but are unable to score well. I've never worked on partial swings and pitch/chip shots, that is why my scores suffer. My putting isn't bad but it's not great, I still have a few 3 putts per round. Typically my bad holes are due to an ob shot/lost ball.
I'm not piling on the s*** storm or anything, but if you are getting the occasional 3-putt and drive the ball really well, you would need to be hitting the ball OB a lot to maintain a legitimate 25+ handicap.
Again, no one cares how far you hit the ball except for you.You won't get any wows or congratulations from anyone on the internet either. What you can get is honest advice when you ask for it. Some of the reputable members here will obviously have a hard time committing their time to providing you with that advice if your numbers don't add up though.
You did make the comment that you fairly regularly drive the ball 300 yards. You do realize that is quite a feat and more than the vast majority of amateur golfers, right? With that being said, the coordination and raw-talent with a golf club that this feat requires is what is bringing your handicap and scoring into question.
On-topic though, you definitely need to work on your short game to compliment your driving ability. Eliminate the OB and wayward shots by identifying your swing faults and practicing to correct them. Work from the green backwards and spend your time from 150 and in. You can clearly hit the ball a long way from what you are saying, so work with your wedges and scoring irons to drop your scores significantly.
(Are your OB shots off the tee, or from the fairway?)