yeah re suspicious activity that seems to be their MO. i appreciate their stance. if you trip up their risk analysis they have every right to stop doing business with you. that's a hell of a lot better than bitstamp's approach.
Some vague warning would be nice before but yes, overall it's an approach that would have much less effect on my blood pressure. I'd be disappointed as opposed to raging.
My Coinbase account is telling me I'm unlimited and I didn't do anything other than ID and proof of address. I think I've put £10 through there in total so perhaps that changes rapidly when they figure out your behaviour patterns.