1.) Is this stuff UV friendly?
Enough so that you can use it with no worries, but you should store it out of the sun, of course.

: 2.) How does the durability compare to more traditional coverings like nylon
: coated with 2-part poly?
Not nearly as strong. But it's still pretty tough stuff. Tom Yost has one that's been around for a number of years, so far.

: 3.) How do you shrink it, or do you just stretch it tight?
Pull it tight. An extra set of hands is pretty useful, sometimes.

Downside: Condensation when paddling, which is one reason why my latest see-thru boat was a solo canoe.