All sites have clauses to shut down any account and seize anything for any reason. So that really is of no help.
I would rather speak to traders who have been using a platform for a good amount of time for references.
Anyone?
It's good to know specific rules. Coinbase will cancel your account if you're sending BTC to LocalBitcoins, etc.
I'm not using the Coinbase exchange, because it's not yet available in my country, but I have been using Coinbase for 3 years and it always worked smooth for me.
I do see that if they SUSPECT that you are using coinbase to buy/sell in a high volume outside of personal use ( kinda like a business ) they will limit your account, which is fair for they went and jump though hoops to get where they are at right now, plus it also limits the liability that they might have due to the idiots that want to do illegal activities with bitcoin.
Except from what I understand Coinbase takes their duties to a whole other level.
People get money seized and their accounts taken from suspicion of fraud all the time.
The reason for this seems to be Coinbase wanting to show the US Gov that it can enforce and closely monitor everything.
From what I have read Coinbase makes it very hard for a person to trade by himself in any significant amount
I am going to get a bitstamp account going.
Then a BTC-e if I can figure out how to use that site.