Would I be allowed to start RPGs that I've done in the past, on another forum, here?
I ask because I had to force a stop to one, due to it getting a bit (VERY) chaotic. ^^"

Of course. If its yours, its yours.

@Ellri thanks.

No problem.

Okay I've actually got another question, sorry. I tend to prefer having people sign up for characters(canon from a show) or tell me if they're going to be playing an OC/FC. So can I do that? Have people sign up when I put my actual RPGs up?

That is generally how most do it here. First they post Interest check, then an OoC where they describe the RP in more detail and provide a character sheet template, then the interested folks will post up characters and (hopefully) get them approved. Only then do most start the RP. But you can twist and change that however you will.

So long as you and your players obey the Guild rules, You can do pretty much whatever you want. In their thread, the GM is god.

We don't mind answering questions, but this guide might provide you with answers to many of your still-unasked questions.