Unsure about the other two, but I cannot see a withdrawal of 175 from a deposit of 100 triggering any kind of audit. In order to trigger document requests, withdrawals tend to have to be larger. Neteller is likely to be the least troublesome, as card based deposits leave the casino open to charebacks. You will most likely be unable to find a card that works, even the pre-paid ones seem to be blocking US players at casinos.
I suspect what triggers a closer look is if you win slowly and consistently over a long period at a game that should get you in the end. It may be wise to retain your own Playcheck records, just in case you do very well and need to defend a claim of "cheating".
Once Vegas Affiliate casinos had the heat turned up on them they paid, as they say, "after pressure from the wider gaming community". This looks like they had a thin case, but were sure that something was up due to said players winning too much with a "system" of play that should not be working.
Roulette systems only work if there is some kind of long term bias in the game, such as a tired croupier or uneven roulette wheel. Online, problems with the software can be responsible, but a casino will not want to admit this as it will discredit the casino's fairness which will probably cost them more than just paying and banning one or two players. Hopefully this is the worst that will happen, paid off, and told not to come back. (I've had this often with the Fruit Machines
).