If I get a membership, can I use it at another retro fitness gym

Yes $20 a month and it covers all the gyms

Yes

Yes you can

Yes you can , and if you sign up at the hempstead one . You can go to any other retro as many times as you want. It use to be if you signed up else where and went to another retro a certain amount of times. They would switch to that retro only .