Many questions I've asked can't be solved in the near future, and since it's become so important to accept answers (courtesy of the accept rate), should I just accept any good answer even though the problem isn't solved by it?
If the answers on your question slate don't suit or solve your needs, don't arbitrarily accept any answer just for the sake of a higher accept rate. 70% and higher is good, but you don't need to shoot for the 100% moon.
Wait some on the lingering questions, it's fine, really it is. Not all questions have to be solved and green-boxed out of vision within a day.
If the information landscape around that question changes, you may see an acceptable answer pop up. An answerer that would have otherwise not seen or bothered with your question if you did accept one willy-nilly.
No. The accept rate isn't that important.
Jeff has said
It is considered good manners to accept answers on your questions, eventually, but accepting answers is not required. I personally consider anything at 70% or over quite good, meaning you accept answers on 7 out of 10 questions that you ask. There are certainly cases where you don’t get an answer you like, or the question is inherently unanswerable.
Although one might question the validity of questions who can't be solved right now. They suspiciously look like subjective discussions.