Quote from OddTrader:
Do you think the following offer from MB is useful?
Q
http://www.mbtrading.com/faqs.asp
Am I charged a new commission every time I cancel an order?
No. Even if an order is partially filled, you can use our "cancel/replace" feature to modify the order's price and/or size, without incurring an additional commission.
UQ
That addresses partial fills vs. ticket charges. I don't know if MBT charges for cancels/modifys, which is a different issue.
Also, it does not address the pacing/MM restrictions, which are exchange rules.
My point is that a strategy like trying to sit on the bid and offer, making markets along with the MMs, is not only unlawful, but would cost a fortune in cancel/modify fees unless you get a ton of action. AFAIK.