Salaam all!

I am a 24 year old male who recently converted (or reverted) to Islam and there are still a few things that I am confused about:

Is it ok for other men (not women) to see me naked? For example at a public pool or locker rooms?

Is it ok for my children to see me naked? Are only my sons allowed to? If yes, is there a certain age that they should stop seeing or start seeing?

Is masturbation allowed? I've been told that it is allowed as long as you purify yourself afterwards.

Is it compulsory to remove pubic and armpit hair? If yes, how often?

Is oral or anal sex allowed?

What do I say in the second tashahhud?

Please help, thanks!