If you do not allow your flock to free range, you are going to have some very unhappy Guinea birds. Guineas really need to go out just about every day (including incliment weather) or they get pretty "cooped up" and get rather agressive.
Guineas can be fairly easily trained to come into the barn/coop at night. They need a high roost to feel comfortable.
I have had the Guineas and chickens (including a good number of roos) live together without an incident.
Good luck. Mine were raised with the chickens from the time they were 4 weeks old and just before maturity, my alpha male began beating up one of the RIR hens. He'd hunt her down. Then all four guineas were beating up the RIRs. They lived in the same coop peaceably till then. No amount of separating, nothing, fixed the problem till I rehomed them. If you have larger numbers of guineas so they have their own society, they seem to do better around chickens, or if there is just one or two guineas with a large number of chickens. I had 4 guineas with 11 chickens, including my BR rooster. When Dodger started beating up my rooster, he was out of here.
Guineas are nothing, absolutely nothing, like chickens and it's a mistake to gloss over potential issues with them living with chickens. The book "Gardening with Guineas" glosses over it by saying "Guineas rule" but doesn't elaborate on it much, a huge mistake and one that caused many to wonder what the heck went wrong.
I'll have them again one day, but they will live separately from my chickens.
I have had keets raised by chickens. I've raised keets myself, I've let Guineas raise their own. Unless your numbers are high enough within the Guinea flock your chances for experiencing trouble with the two flocks down the line are high.
Spring and Fall are the most likely periods during the year that trouble is liable to happen. There is major fussing and fighting going on amongst my Guinea flock at the moment. But it remains in the flock because my numbers are north of 20 birds. If I had only a few that fussing and fighting would be focused on the chickens since they would have no one else to pick on. Its part of their wild genetics and part of their survival to behave like they are now.