Questions about Git that I didn't find anywhere

I've been using github for a while now, and I've been reading the new docs for the Great Git Migration and I have a few questions:

1. Will I be able to create and push unlimited branches (with any name), even if I don't create a Project Release for that branch.
2. Will I be able to delete branches and tags as easy as I do it with Github.
3. Will I be able to fork any project, even if I don't own or co-maintain it?
4. What about Pull Requests, will that work? How?

Thanks