One of my questions is unanswered. Perhaps there are very few people who would know how to adequately answer it. Is it "okay" to leave a question this specific unanswered? I'm wondering if I should delete or modify it, though I think in its current form it adequately depicts what I'm looking for from an answer.
The question is opinion based, but that seems to be your intent. Generally broad opinion based questions are closed because their answers are too subjective. You are asking for the opinion of current MRL members and I think that specificity is a good thing.
If you can improve the question with an edit, go ahead but I do no think you should broaden its scope. I would not vote to close this question myself and hope that someone from MRL can answer it. However, if Stack Exchange users vote to close it on the basis of being opinion based, I would not object.
Questions should be edited, or deleted for a variety of reasons but remaining unanswered for a long time alone is not justification for closure. Very few SE sites can maintain 100% answer rates long term.