Those are some points I hadn't much considered.
I don't think the timezone issue is too much of a worry, because it isn't like we get responses horribly quick as it is. The current membership is US based for now, but many of us are night owls or early risers, so I think there should only be a couple hours in the middle where there might not be a prompt response. Once we get going, we'll see how much of an issue it is, I think and then address it accordingly.
As for languages, I really hadn't thought of that. We don't get many people who can't speak English at all, and on the Board we have a couple who are at least proficient in other languages. Past that we can direct people to others who do speak that language should the need arise as you suggest. I think keeping a list of regions dedicated to a certain language is a fantastic idea. We've had it come up on occasion that I've seen.