The BTC/USD limits and market restrictions are certainly not a long term solution for us. However, in defense I have to say that there is generally no "right" to open a position on our platform, especially on our BTC/USD market, which is still in "experimental" mode. We try everything to avoid this, but if we are out of funds to hedge positions there is no other solution.
Additionally, we have a different risk management strategy/pool for every market; so we cannot simply cross-finance our BTC/USD market with reserves from other markets.