Answers from learning to glide in the '60s....before an expert leaps in..
what the Winch Launch is like
First time, very exciting. Second time, third time, ....... ad infinitum...ditto.
at least 45-55 degree.
The angle of the fuselage against the horizontal may not quite as much as that, especially at the top of the launch where you almost level off before releasing, but it feels like it. The aircraft is climbing due to the lift generated by angle of attack and airspeed, and the angle of the take off path to the horizontal MAY be of that order......wait for the expert, I'm out of my depth..
How much G-Force is experienced on take-off
1G, felt in your back while your feet are almost above you.
After how many flights can you start ridge running
If you are flying off a ridge, eg Dunstable, you'll probaby do some ridge-soaring on the first flight if the wind is right. If not, eg Lasham, you'll go looking for lift to soar in, or just complete a longish circuit to land, depending on launch height achieved and the conditons.
All in all a fabulous first time experience, greatly to be envied.
Edit: The expert got in ahead of me!