If I remember correctly, ustocktrade labels stocks as "limited liquidity" whenever there isn't a buyer or seller lined up for a specific stock. If a stock is labeled as limited liquidity you can't market in or out of a position. I never seriously considered this an option because I couldn't stomach the thought of not being able to close a position with a market order.
That sounds ridiculous. I'm pretty sure you can always exit a position with a market order and execute at the NBBO. It's a very low risk trade for them: they execute your order at the NBBO and then immediately liquidate their position at that same exact price at another exchange. They might even get paid for the order flow. Then they collect the $1 order fee from you.... And on top of that they charge a $1 per month fee and they're most likely collecting interest on the money in your account.
If I was 18 and undercapitalized (as all 18-year olds are), this place would be perfect to learn to trade. Everybody needs to blow up a couple times and learn the hard way. This place is perfect for some young kid with a couple bucks to learn the markets fast and blow up his small account instead of a $25k account.
I started trading when I was 15 and spent my teenage years winning big, losing big and blowing up. Those were very formative years and the lessons I learned is what eventually made me a profitable trader. Because I tasted the highs of winning at such a young age, that's probably what kept me going through difficult periods later in life. I was able persevere and attempt something so stupid and difficult as being a consistently profitable trader.