I thought to segregate this question on Hokkaido from the original. I'm still interested in the other points.
3. I won't drive, so must rely on public transport and walking (over reasonable distances).
4. Would Hokkaido suit, owing to #3 above and the last paragraph here ?
If not, I'd rather research other travel destinations.
Hokkaido is great, although transportation there is far from perfect. While relying on public transport only the easiest places to visit would be Sapporo, hot springs around there and Hakodate.
Taisetsuzan is amazing place itself but there's nothing to do without a car, unfortunately. Of course, buses do run, but travelling from one place to another place is quite a distance and would take very considerable amount of time.
