As WJB says if you choose a control tyre it has to be a deep treadd tyre ot help iin the damp/cold/wet. This is a good idea and something like the Bridgestone 090 or similar would work well. Also takes another decision out of your hands and frees up a bit of your mind to think about the race
I've spent plenty of time before a race wondering which tyres to fit and rushing around changing wheels with 2mins to go. it isn't fun so I do agree a control tyre is a very good idea as long as it's a tyre that works in all conditions
As for warmers I wouldn't outlaw them as telling someone they have to race on cold tyres is a little risky in this daft lawsuit society. I'd leave it a free choice. If you have to buy a genny and warmers they are things that can be very easily sold should you wish at the end of a year, also if you drop back to t/days they can be used to improve tyre life.
Good luck with the series it will be one I'm watching closely, at least when I'm not kicking weeksy's arse in our series