Had a 12.5' aquacat for about 5 years now. It's a bit of a pig, but usually that's due to our gusty monsoon winds in southern arizona on small lakes with lots of terrain (and a lack of ability)
My main question: the back end of the sail is grommeted to a pulley which attatches at the absolute stern of the boat - it slides on a pipe running from the port to starboard rudders at the corners of the boat, only it's just a piece of plastic on a pipe, so it really doesn't slide, especially with tesnsion on the sail - now it was obviously designed to move from side-side, my question is why, and am I losing alot because it won't slide? I used to play with it alot, but it never seemed to make a difference, so I just left it in the middle and it stuck there.
Somewhat related question: I can't seem to execute upwind turns, especially in light conditions without a stall, it's gotta blow pretty darn hard for the boat to maneuver nicely. The mast attatches at the very front of the boat and angles backwards. Anyone ever stick a pole out front and attach a jib? Bad idea? Totally naieve? Course, the non-vertical mast might make a jib impossible anyway? Thoughts? Buy a hobie? Just sell it and stick with my sailboard which I love and seem able to maneuver instinctively? Learn to sail?
Thanks,
Steve
Yes.. 
Steve,
I'm having a bit of difficulty picturing the set-up you describe. Are you saying that your mainsheet is linked to your tiller bar in some way? 
As for a jib on a pole - it's not a naive question. There's no reason why you shouldn't be able to make it work, but perhaps it would just be better to sort out what you already have. Any chance of posting a few pics of your set-up and boat so that a few more people can chime in with advice?
Sounds to me like "the piece of pipe" he describes is really the rear beam and the piece of plastic to be a jammed traveler......
And yes, learning to sail it would be a great idea but you are taking your first step by admitting you have a problem.
I'm Steve and I am a Cat-a-holic......
I'm not familiar with the Aquacat setup but I think what you are describing is the traveler arrangement. If so, it should slide out to the leward side when going downwind and be centered or close to centered when sailing upwind. As for tacking, try moving to the back as you tack. This shortens the waterline so less energy is needed to turn the boat.
The Aquacat has a raised traveller bar connecting the hulls. See pic; also see the American Sail website.