>So, no holes in the gable roof ends, ok.
Maybe one hole at one end... you may need to experiment. My point is that they are better off with one opening than too many. Huber's observations are that they get LESS ventilation with more holes... but then he wasn't trying to create any kind of chimney effect.
> And I need no insulation in the top either then?
You can insulate the top if you like. Mainly, though, if it's not in direct sun and there is a air gap between the cover and the top bars to let the heat from the cover dissipate, you should be fine. Some of this is also how sudden and fast a flow is and how much new soft comb they have that is heavy and full but not mature and strong. A collapse is often a matter of timing more than anything and often that timing is out of your control.
> And perhaps legs for the hives...
In my climate they blow over with legs on them. I would just set them on bricks on the ground and use a stool to work them.
>Oh and I had planned for screened bottoms, is this still ok for the ventilation issue?
If you have them closed they may do ok. I would not have them open.http://www.bushfarms.com/beestopbarhives.htm#SBB
I would not bother with them myself.