I have a finished horse that is not getting in the correct lead to the first barrel (right). He can pick up both leads fine during training but 60% of the time I send him down the alley he leaves off in the wrong lead and messes himself up to turn. This has really taken a hit on my confidence and has me only expoing everywhere instead of running. This horse will not take a bit either, at all. I have tried everything and I can only run him in a hack, the thing is, when he's close to full speed, I cannot get him to stop. He listens perfectly fine during slow work.

Try switching the other direction running the pattern. 

Get a good lameness exam. Finished horses don't just start doing this kind of stuff for no reason 

I agree with the other poster. You have a finished horse that is trying to tell you something hurts. Most of the time, that's the reason for running by a barrel.

Take the horse to a good lameness vet and figure out what is going on.

I have before, and the only thing wrong was his hip was out of place and is fixed with regular chiropractor visits.

How long have you owned this horse?

The first thing I would check would be teeth. The second thing would be an exam by an EQUINE vet.