Did someone call for a compulsive writer to give an unfounded opinion?
Quick and dirty:
1. A lot of brokers have at least one NFA action. More than one or a recent one that's bad is cause for alarm.
2. Multiple reviews about money problems is a big red flag in my book. Then again, all the reviews on this broker are fairly old. Customer service and policies do change over time, and occasionally improve.
3. If you want to risk it, open an account with a little more than the minimum. Then make a few small trades to see how good/bad execution is. If it seems ok. then try to withdraw a little money to see how much hassle that is. If the execution seems bad, pull out all the money and go elsewhere.