I love time-travel stuff, although I've never tried to write it. The funnest thing about it to me is all the different interpretations of the act of time-travel that people come up with. Time travel is a hypothetical (theoretical?) concept. Nobody has done it (to my knowledge) so nobody can say anything definitive about it. And so what if they could? What if time-travel was common and we knew everything about it? The wonderful thing about fiction is that it takes you out of the real. Good science and well-formed theories are fine, but they shouldn't get in the way of fiction. Good science is wonderful. Good fiction is wonderful. For a creative writer, fiction should come first, science should come second. I'd try to avoid plot holes, but I wound't let it what people might think about my time-travel 'science' get in the way of my having fun with it.