Hey, i'm new to the hot tub world as well. I've currently fixing and getting my hot tub back into prestige condition.
You have too many questions in your post for one person to answer them all properly. The most crucial part of your hot tub is the plumbing now. Like any plumbing problem, you have to fix the leak first. Where is the leak? at a connection (T, elbow, jet) or is the leak on the pipe? If the leak is at a connection, you will have to cut it out and retrofit the connection. if the leak is on the pipe you can get a coupler and cut the pipe in half and couple the two pipes together. Fixing the leak is the most important thing to do at the time being.
i've seen people turn their tubs on the sides to fix the plumbing.(obviously you'll need some muscle to get it up on it's side)