1. I'm thinking they start off as an unconnected party. Maybe they are a group of online friends who regularly discuss the animus tech, or are interested in it otherwise. One of them gets their hands on one and covertly informs the rest of the group. Then they all decide to meet. Based on what they discover through going back in their bloodlines, they find out who their ancestors were and decide how they will align themselves... assassin, templar or otherwise. Or maybe they don't want to align themselves at all, merely want to do research, but get dragged into it. They will eventually get discovered.

2. Good question. What do you think? I think they should probably start off going through their own bloodlines. Afterall, this tech hasn't been seen in 10 years, so they will only know how to operate it based on what little they've been able to read about it online. So the thought of being able to go outside of their ancestors history won't initially occur to them. But I think definitely they should be able to go beyond that eventually.