You want to be able to leave poor feedback for someone you didn't transact with because they didn't answer your question? This isn't facebook where you engage furiously with people at will. P.S. You don't know that used gear is no longer covered by the OEM warranty and that the warranty only applied to the original owner and only if purchased via an authorized dealer?
Seller Silence
On two occasions during the past month I have posted a question to a seller about whether the item still has a manufacturers warranty. One selling an Aurender N20 and the other a JVC NZ700 projector. Neither has responded even though it has been a few weeks.
There should be a way to leave seller feedback before a sale to inform potential buyers of this issue.