Yeah, that format doesn't seem like much of an auction when you have a reserve (BIN), you might as well pull a FFB and put it out there with a mongo price tag but note you're "taking offers".
A true auction is best (either using the new-once-twice-sold format, or the set-your-snipe/fixed end time format), but I suppose to avoid the threat of shilling the seller would have to require that bids be posted directly in the thread.
Agreed - posting of bids in the thread has to be mandatory. (Which, btw, I did require in yesterday's format.) They would otherwise be unauditable - similar to a Heritage auction (silent bidders).