I don't think there's any way you can check how small the transistors are with BFGMiner, however your card should be a 28nm miner. It looks like only 28nm Monarchs were made.

Also, for the hashrate bit, trust the hashrate displayed in BFGMiner. The pool hashrate is just an estimate at how often you submit shares and what difficult they are, and often the estimated difficult is off by quite a bit, as in your case.