Matt:
There is NOTHING wrong with what you are doing. I am going to go out on a limb here, since I am not a board member, and say that the TDA rules are not "cast in concrete". There a many, many card rooms, casinos that have one or more exceptions to the TDA rules in their day to day operations. These exceptions are made for a multitude of reasons, some are mandated because local or gaming agency rules mandate a procedure different from what the TDA has adopted as a 'standard', some are made because of individual preferences or because 'that is the way its always been done'. If you look at the history of the TDA, you will find that standardization on a single set of rules is a long term goal. Even at the last summit, we had several discussions where one or more of the larger Las Vegas poker rooms have made exceptions to one or more of the adopted rules.
So, while I agree with Jan, that taking a player's chips is an extreme solution, it may very well be the exception that you needed to take to make the operation of your games more in line with the overall goal of the TDA.
Just remember, as Jan said, to post your rules and note exceptions. That way there can be no question about how you are going to run your events.
Hope this helps!