1) How the hell do you get qualified to fly off a winch in the US ?

Where in the US are you? There are a couple locations in the Northwest
where you can get Ground Launch Endorsements.

2) How much land do you need to run a winch launch that can get the
glider to 1500-2000 ft altitude ?

Most of my Winch launching was don on about 4000 feet of cable.
Launches were between 800-1200feet. Which is great for training. (Wnd
conditions can vary the alititude siginficantly)

I have done AutoTows out in the desert where about 2 miles and 3000
feet of cable will get you 2000 feet

Brian
CFIIG/ASEL