Answers:
1) You don't even need to search for this one. There is a sticky in this board called "If you're looking for allies" or something like that. I suggest you read that first.
2) Yes.
3) You can make your own. There are topics about this all over the place. Iw ould look into the models and media board for a few posts about it, though, first.
4) With the latest updates, yes, and... yes, it kinda is hard if you're not entirely sure about what you're doing. I believe there is a thread floating around here on page 1 or 2 of this board about making a shopping system.
5) It's a little thing that has been lovingly named the "FPSC Hints and Tips Guide" by Nickydude. It can be found in a sticky thread in the FPSC Chat board. Read EVERYTHING in there and you will be pretty much on your way to making nice games in FPSC.
No, you don't have to use the characters they give you, but if you make your own, it does take quite a bit of effort to get different characters working in FPSC, mainly because you need to make sure that you model them in a way that is compatible with FPSC. Things like animations and animation numbers (FPSC related, not model related) also need to be set up accordingly. In fact, unless you're already really good at modelling, I would suggest just sticking with the characters provided with FPSC, or the ones in Model Packs/TGC Store/Models & Media board.
As an after note, I suggest you figure out how to get the search function around here working for you, because people won't be so lenient after a while, especially if you ask lots of questions that have been answered before.
The one and only,
