Good poll BH, in that you put an Other option in it. This is another good attempt at collecting information. Knowing the situation at hand and keeping up with the discussions, I would automatically vote "No Restrictions".
But... I firmly believe in the 10 turn limit per T/C, with the few extra turns allowed for
special circumstances. The amount of T/Cs per week should be limited to two, unless the is an "online pre-turn move" to determine an outcome needed for a decision (you know what I mean). These are the basic structures of a Turn Chat. All other tweaking is up to the President/DP. There should be no minimum, as the T/C can be ended at the President's discretion. People who want to play 15+ turn T/Cs should be kept in stockades far from any computer.