Nobody would know it for sure, espcially if it ends up in the court. But the reality is that they hold the deposit in escrow right now. If you want to get it back, you probably will have to sue first.
2. 如果房子回到市场上,卖价真的低于我的价格,我是否会被起诉?
Nobody would know it for sure. It really depends on the seller and whether he or she wants to chase after you for the difference, of couse, assuming they do have a case against you.
3. 如果SELL RELATOR claim COMMISSION, 会从我的定金里扣除吗?
This probably they cannot do, but they can sue you for the commission earned. If the court you materially breached the contract first, you will have to pay it out of pocket.
4. 如果需要上法庭解决,我的律师费谁付,是输的一方付全部费用,还是各付各的.
Most likely you will have to pay for your own legal expense.
My feeling is that your attorney gave you a bad advice and you made a bad decision.