if one places more than one order, where each order is @ max margin, is it possible that more than order gets filled?
If you have like $100 in your exchange wallet then you can put a bids for 100 BTC at $1. Now the system assumes that these may get hit at some point and that you should therefore be able to place sell orders for them in advanced, so now you can place a 100 BTC ask at say $720 and rustle people's jimmies. Now, if this ask is hit then it will just cancel since you don't have 100 BTC - but you can place the order.
What? That seems like a serious design flaw to me. So you can basically bluff and manipulate the market that way? To be honest I can't believe they allow this.