If your coop is ventilated well, has good light and the chickens can have water and food then 1-2 days will be good.
If your run is not to big and no chickens can escape then you won't have to keep them locked in the coop at all. They will just venture around happily and can't run off.
With roosting, all chickens, excluding perhaps silkies, like to roost on the highest bar so as long as there are no higher parts than your roost bars than they should all go up fine. If not, then you may have to keep placing them on the roost bars every night until they get it, which wont be long.