[Maru]

If moderating to the letter is going to be too difficult (which it sounds like it will be), I think stick to public warnings and thread locks.

When you're deleting threads and posts for simple rule breaks like being off-topic, you're leaving things open to interpretation.

I think just a simple warning to tell people that that is not considered on-topic and to get back to the OP's post will suffice. The people who would be annoyed would be satisfied to see this public warning posted and well--if the thread crashes... then thread lock.

The OP should have the most control I think. They should be able to say, this is the discussion I want to have--within these parameters... I don't want to discuss XYZ, I want to discuss this issue and the merits/non-merits of it. This creates an equal environment since people who are right-leaning can have as many threads as they'd like about conservative topics and so can left-leaning folk with social justice topics... everyone is happy, as long as they keep to the OP.