lisalisa, i had two giant rabbits which had the run of the garden all year, i only bought them in for one night when we had a particularly bad frost. I never had a fox problem as we had a big dog at the time.
Rabbits really should have a hutch though, if they can run free in the garden during the day all the better but for most people this is unacceptable as they decimate your garden. I would be inclined to keep the hutches raised with drainage holes as this will prevent them getting sodden.
As far as feeding goes, the school of thought is the moment is plenty of hay, green vegetables (NOT lettuce, this is actually extremely bad for rabbits and of no nutritional value as they cannot digest it). Be very careful which rabbit food you buy, if you can get them used to something like super rabbit which is all one constitution then this is better as many of the ordinary rabbit foods are full of those green squashed peas that the bunnies love, but they are high in fat and fill them up, they then dont tend to get the other vits and minerals they need.
Some rabbits do have teeth problems, their teeth actually dont stop growing and they are kept down by chewing. Due to poor breeding many of them have mal aligned jaws and the teeth do not mix resulting in them over growing, this requires visits to the vets to keep them in check.
Very important that you consider vaccinating against myximatosis and HVD and most practices offer this on a yearly basis (it used to be every six months). Unfortunately both of these diseases are present in the domestic bunnies these days.
Another important thing to do is keep an eye on thier bottoms, if they get a dirty bottom it could be an idication of an upset tummy or teeth issues. The problem with this is fly strike, very dangerous and can kill within hours, basically flies lay their eggs in the poo which then hatch out and the maggots burrow under the rabbits skin, its nasty and particularly a problem in summer.
So, now ive told you all those horrible things, you can pack them back off to the farm You sound like a good owner though so i cant see you having any problems.
Hope this is of use x