Ah, good to see someone else getting into this. I say you wait in London. Knowing how things work, London will be both the problem AND the solution~
Don't forget Cardiff. That place has the rift, not too mention all the other things that happened there
Heh, I suppose only some of it. But he's certainly the source of a lot of different kinds of disturbances. He's getting kinda old though, so if they're planning on making another Torchwood, they better make it soon, just because he won't look like the Captain Jack Harkness we've all gotten to know.
no, he's going to(well, supposed to in the series) stay the same throughout time. That's what they explained in Torchwood. He doesn't die, and he also doesn't age, unlike what happened with everyone else during Miracle Day.
Whatever you do, don't eat the yellow snow. Things will start looking even more out of what than they are currently.