Boy you ain't lying about the control - jenky is a good term. Are you leaving the cable trough in? If so, it's not hard to change cables to the engine or the console.If you can put up with it for the season I would consider it.
I think you'll find that the existing floor is about 5/8" with glass so you'll have a little height difference going with 3/4 plus glass.
I went with 5/8" which is actually close to 1/2" in thickness - that's what I would use - 1/2, which will be less than 1/2" will be too light I think unless you are light yourself.
I left the lip and will put the new sole on top because it will make it much easier to tie the sole in. You can see from the pics on my rebuild, there is nothing in the corners to support the edge of the sole.
I would glue it down and weight it down with everything you have in the garage. Are you using poly or epoxy?
The difference is how you can cover it - poly you can cover in gelcoat, epoxy can not be gelcoated. What your finishing plan is dictates what you should use.What to use to stick it down also depends on how long it will be down - if you are just doing a quick fix and will gut it later, then I'd use poly on the deck laminations and thickened poly to stick it down. If you are not going to redo it later, then you can think it through a little more and possibly use epoxy.On my rebuild I used epoxy below the deck and poly above.