Yeah that'd be a good idea to double that sounds like the best idea I've heard. 
Hmm, that makes sense for him to crash land where she winds up although I was thinking that the 'cracks in the universe' could be a plausible explanation as to why Rose got here. He reset the universe when he did that and so, maybe she got dragged there as he wanted things to be as they were but I can think up other ways for her to be there. A rift could have been open [currently watching Torchwood and they've got an episode about it] and she walked through it and wound up in this universe after the meta crises finds someone else? And then we could decide on what episodes we could do or something and then go from there once we got comfortable. And I'm pretty sure that I'd make a muck of things playing as Eleven. I could possibly get his childishness down, heck get me hyper enough and I could be Eleven :3 but I have Rose's character down and re-watching from series one is certainly helping me
Yeah total overkill to use both the TT and the potion discovered by serendipity {it's my new favorite word and it would fit the 'discovering something by accident' thing we got going on. Plus it does mean 'happy accident' so it works two ways :3} Hmm...I think that the war aspect certainly has its appeal since he could take it by mistaking it as his monthly medicine. {I forgot what it's called but I'm certain it's something ironic and degrading since Snape did invent it.}