Sometimes people ask questions and does not come back. Other people answer their questions, post comments to ask for other related things. But no reply from OP. If a question is asked and other people are helping, OP must respond. What to do with such questions?
If they are reasonable questions and contain enough information to be answerable, just leave them alone. They may be useful to other people encountering the same problem.
If more information would be necessary to answer them properly, vote to close them as "Not a real question" or "Too localized". This is something the community can handle, so no need to flag if you have the reputation to vote to close.