I am probably soon to become a nomad. Not emigrating to any particular place, but not being exactly a tourist either. I plan to stay in one place long enough to learn the language, meet some people, and maybe even make a contribution to the community. So some of my questions will be an obvious fit for ex-pat, and some for travel. But some of them will be on the fence or perhaps suitable for both. What are the chances of developing more criteria for distinguishing?
I'm slightly hesitant to phrase it this way ("tourist" has such a derogatory ring to it), but I think as a rule of thumb "travel" is really for tourists, not in the nasty "you look like a tourist!" way, but according to the Wikipedia definition. Ask yourself if the enlightened tourist would benefit from your question, if not it probably doesn't belong here.
I suspect some of the confusion around this could be avoided if this site were simply called "tourists", but as I say it has a derogatory sound, not to mention that we wouldn't want to attract undue spam from the tourism industry.
From your description, your questions will most likely fit into Travel.SE.
Expats.SE is more into questions about how to deal with different requirements in a country where you moved to for a long period of time while you are not a citizen of that country. That includes, bank accounts, work permits, education, tax, etc.
There's always going to be some overlap. If you're every unsure, hop into the chat rooms of either travel or expats, and someone can give you some advnce :)
Much like The Great Outdoors has some overlap with travel, some questions are 'on topic' for both sites. There's still obviously some distinction and questions about relocating to a new country are still more for expats, but if you're passing through, rather than settling, it's a good chance it's for Travel.