I'd like to close the loop by explaining the source of my misunderstanding, in case someone else has the same issue: I was confusing cash with available funds. The maintenance margin applies to the available funds, not cash. I can indeed use all my cash balance to buy securities.
^ hard time understanding what that means, but even if you had no cash, it's no difference then if you had cash sitting on the side... you can buy securities ( stocks ) with the cash, but keep in mind the more you buy, the less margin you can borrow.. the rate on that at IB is you can borrow 3/4 the amount you have total ( stocks.. ) so say you had one million cash, you bought 1 million in stock, you now have 750,000 available for margin to buy FOP's. keep this in mind as you had FOP's, so essentially buying stock also decreases margin cushion you have, whatever it is, as I said by 1/4.. the only thing I've seen not do this is buying treasuries, treasuries go at the rate of like 1-5% or something vs. the 24% if you buy stock.. hope that helped any instead of confusing