Welcome there.
1. You can get the WhoisGuard to protect your domains whois information on the Namecheap. I do not recommend you to put any fake personal information, you can very easily lose your domain because of it.
2. I am not sure if I understand what you try to say. You can upload/embed videos from adult video sites such as xhamster et cetera. Of course you should not violate any copyright infringement laws.
3. Videotube looks great, you can check here some themes for tube sites:
Themes | Wordpress Tube Themes
4. Just put the embed code on your posts and that is it, not need to use any players.