Anyway, the rollover won't stop money laundering per se but it would discourage them from using the site for money laundering. Imagine if the site didn't have any sort of rollover. Criminals would be all over it and it would def bring the Feds coming after the site.
I don't think the rollover is the big concern... most sites do have rollover and although it's a little bit scummy (essentially ripping into your balance every time you deposit) it's not terrible.
Reading it again and again, I'm quite sure the 'at least minimum one bet 50% requirement' is across multiple bets. It said 'at least one bet', so meaning it can be multiple bets.
I can twist the equivocated semantics into either, "bet 50% of your deposit cumulatively," or "one or more bets at a minimum stake of 50% of your deposit."
If I read it left-to-right, the latter is the only logical conclusion that I can glean from the clause. Here is the compartmentalization of each semantic category:
[You] := subject
[have to make] := action
[at least one] := quantity
[bet] := object
[with minimum stake] := descriptor
[of 50% of your deposit] := details of descriptor