>1.) Do you experience less mould on combs? Different types?
>2.) Do you paint your cedar equipment?
Sometimes, but usually not.
> If not how does it fare in your climate?
I don't paint most of the pine ones either:http://www.bushfarms.com/beeslazy.htm#stoppaintinghttp://www.bushfarms.com/images/EightTenEightHives.jpg
> Do you live in a wet or dry climate generally?
Coming from Western Nebraska and Wyoming I would have said it's wet here, but it's been pretty dry the last few years.
>I just started to build cedar screened bottom boards and was thinking of trying to make up boxes and frames of cedar as well.
If you have scraps it works fine. If you have to buy it, I'd buy pine because it's cheaper. I've got 30 year old pine boxes with bees still in them.
>Its my understanding that cedar has a higher insulating value
I doubt that it's significant though.
> and is very good at keeping moulding at bay without painting.
It weathers better.
> I live in a wet climate, and have access to A LOT of cedar, so I was thinking of making thicker cedar hive boxes (two inches).
I think that's a waste of wood. I'd make them 3/4". If you have access to inexpensive cedar it makes great boxes.
>If varroa weakens a bees immune system and makes her more susceptible to infections, I guess my thinking is that cedar boxes would remove more of the spores and moulds inside an unpainted box during winter especially when the wet seems to permeate everything here.
Mold is not what is killing the bees. It's viruses that only live in the bees, not in the boxes.
It also makes no noticable difference on wax moths, in case you were hoping for that.
Cedar is light in weight, and lasts a long time. If I could get it for the same price as pine, I'd buy cedar.