P.S. How do I increase decrease work area footage time (other than initial new project) especially with open composition?
For your compression questions, please do a generic search on Google about AVCHD, H.264, Quicktime CoDecs and all these things. This has been and is being discussed a gigazillion times and you can find enough archived posts even here on this forum. It's a complex black art and since you didn't provide any more specific details, this could only lead to an uninformed, infinite, but quite aggraviting thread for all involved. Read up on the basics first, then come back with specific questions.
....it's an 80Gb that's split for footage and renders...
Oh, isn't that just the cutest tiny-little baby drive?
For a hundred bucks or less, you can get a 500GB external hard drive and your problem's solved. Spend some more and get a 1TB drive. Storage is cheap.