What effect does setting margin to zero have?

I know that new trades will not be taken, so for example if you are off on your holidays, you can set it to zero before you go, knowing that open trades will be managed and no new trades will be taken. A useful feature for the paranoid, or those who think everyone should stop trading in August and December.

but,

1) what happens to new phantom trades when margin is zero?
Are they not taken also?

2) Are the skipped trades due to margin being too low taken as phantom trades? Would this be worth implementing?

3) Would a period when margin is set to zero influence factor F? Margin = (slider x optf x F) and ensure that on resumption of normal margin all trades are taken?