Yep, it's a good idea but I actually prefer forums having more than 2 pages of topic list. Well, at least for now...
Forums will be pruned of really old topics when it's needed. (Really old = probably about 1 year) The reason why I like the forums to keep most of the old topics together with the new ones is because not everyone had come here at the same time. It would be better if they could just go back the previous pages so they'd see how the forum was like before and they'd know what was already discussed.
I don't quite get what you mean by an archive. Is it like each forum will have its own archive subforum? Is that what you mean? If yes, I'm okay with that idea.
Although I don't think every forum here really needs one. Well, the Anything goes... forum definitely needs archiving.