As far as ToS, if I don't read it then I don't bitch when I lose money because of my failure to read and understand it. Just like any other contract I agree to. That's part of adulthood.
I hope you can appreciate that when most people see a mundane contract or a "terms of service" they don't expect there's a need to get lawyers involved and just assume they're reasonable. I've logged stats of how many people click "Show Terms" before agreeing, and it's <1% of people even glance at it, let alone study it. This should be used as a chance to do right by your customers, not as an opportunity to selectively screw them.
Actually, this reminds me of Bank of America. They had in their terms:
a) If you use your account when you have no funds, you have to pay an overdraft fee ($35?)
b) They are allowed to re-order transactions that occur in the same day
So what they did was re-order transactions in such a way to maximize the amount of overdraft fees a customer needs to pay. They would put the larger transactions first so the account would be overdrafted, and then charge the overdraft fees over and over for all the small transactions, even though you really had funds in the account at the time.
It was totally allowed by agreements customers signed, and I'm sure you'd defend it, but it's total predatory bullshit. And the law seems to agree with me, they ended up paying a $410 million dollar settlement over it.
The same applies to bitstarz, I'm sure they think they're really clever with their little "gotchas" they left in the ToS, and I'm sure there was a lot of excitement when they realized they could take ~$8k USD from btcgambling's account because he accidentally broke a rule (that their software accepted), but excuse me for not taking the same interpretation.
You can keep calling it "predatory" or "little gotchas" or whatever else you want. The bottom line is it's extremely common among online casinos. I play in many different casinos and this is a very common rule. Seriously, get the fuck over it and move on.