I used 1/2" tape. I bought it from RS Hughes (rshughes.com) which had a local outlet. They often didn't stock it but brought it in from another store. The 1" wide tape seems to be stocked more frequently. I doubled the tape so I actually had 1" wide adhesive on all seams, including the beaks and tie-outs. If you do that on the ridge, make sure there are no gaps or water will work its way in through capillary action. I used 1/2" tape rather than 1" because I knew I'd be needing 1/2" for other projects. If I were just doing a tarp, I'd buy the 1" and be done with it (or buy a roll of each if you think you'll use that much).
I cut the tarp with a 2' metal straightedge and a razor blade against some medium heavy cardboad--you want the razor blade to extend into the cardboard a bit. I have also found that a really sharp pair of scissors can be used if you don't try to "scissor" them, but just hold them open and slide them through the material (hard to describe but maybe you can experiment and get the idea). But the scissors have to be really sharp and there's a knack to it. I have never tried a rotary cutter.
I did not hem the edges--they don't fray (at least so far). You could hem them, but it seems to me that the only thing that might cut down on the flapping would be to give the edges a catenary cut--that's just a hypothesis since I haven't tried it. I notice, however, that some folks that make cat cut tarps do give the edges a cat cut, too.
Puncture resistance was tested "by hand" vs. silnylon. It "felt" about the same with a really sharp object. I doubt that hail would puncture it unless you're talking about really big stuff. I've had light hail on it and aside from being noisy, it didn't have any effect. Pine cones, depending on size and how prickly they are could be a problem. Sharp, needle-like things go right through without much effort, but they also easily puncture silnylon, so I'd say you're no worse off. The heavier the film (of the cuben) the tougher it is, of course.
Rain chaps would give me pause. Depending on how much brush you intend to go through, they might not last very long. Walking through long wet grass would be fine, as would "soft" brush. But if there are stiff twigs in the brush, you'll get quite a few holes, I'd think. With my pack, my body tends to hit the branches first and sweep them aside so they don't hit the pack as much as I think they would your legs. Also, I'm really really careful with the pack--if you were walking through miles of brush and were as careful with your chaps as I am with my pack, you'd be doing about .5 mph. Just so you know, I considered cuben chaps and decided to use Dripstopper pants instead for the northern Washington section where I'm expecting tons of rain.
Thanks (to everyone) for the compliments.