Guinea Fowl: can adults roost on large rocks?

We have land in N Alabama with several large boulders. They are about 6-8 ft tall and flat on top. They are about the same depth and width, too. I think they would be safe up there; or safer. We don't have many predators, except raccoons for eggs/ keetes. I'd like to follow the info on other threads re: a coop for them when young and feeding and water, but I'd like them to be more independent as adults.
I have lived at a home where they roosted of the roof, and most survived. Them getting in the road was more of a problem there. We have a spring fed pond that deer and others drink, so that would be an option they would have. And since we have 15 acres, and maybe adding an additional 15, I'd rather them spread out anyway.
I'm putting in a couple acre food forest, and we have some forest and open areas, so I'm looking to them for tick and insect control and as an early warning system, which I know they do both!!

I can build some perches or a roof over part of one of these if needed?

I'm planning on starting my keetes in the Spring, so they will know home by Winter.

What organic food do you suggest?

I suppose they can roost on the rocks but I always provide some kind of poles to perch on.

The best low-interaction guinea coop I've seen was an enclosed roost built up on stilts with some sheet metal fixed around each leg to foil predators. All it needs is a couple walls on the NW side, a roof and the four stilts to hang it all on--don't need to build a floor or a ladder since they will fly in and out.

I have even seen guineas kept "free range" inside a 4 or 5 ft enclosure. They fly over the fence to get in and out--also a low maintenance option.

The question is just keeping keets alive to where they can handle it on their own as usual.

I used to start mine on "turkey" feed or any other higher protein poultry feed. The organic thing mine ever got was garden scraps and stuff they foraged on their own.