I can help ya. From what I've learned so far (my guineas are 6 weeks old now) guineas do better left pretty much alone, as in not cuddled and held like a chick. The few we held and made friendly were the ones that died.
The rest have done fine as long as I let them be. Go figure!
YES they fly! They fly into our trees, up on the roof of the coop, even up to the first roof of our house! They fly VERY well at a young age. We clipped the wings on ours for now to help them learn that this is home, and its worked great.
Ours share the coop with our chickens and young chicks, and even our 2 turkeys! They get along great with everyone so far, and follow what the chickens do (like going back into the coop at dusk). In turn, the chickens have learned to take head in their warning calls, and my roos become alert and aware when the guineas sound the alarm, and the hens and chicks run for cover. They all eat the same feed, which is a mix of layer/grower crumble. They forage more than chicks and eat ALOT of bugs, and grass. They get into trees and pick bugs off the bark. They look under logs and eat the bugs crawling there too. Flip over a rock or two for them and the bugs will be gone in no time!
You will not know if they are boys or girls until they are older, and sometimes not even then, as they will look exactly the same. No one that I know of offers them sexed because they are so so so tiny as day olds it would harm them to try it. I have seen no aggression of any kind in any of mine. In fact, they are quite mellow and peaceful, unless they are on alert about something. Then, they dart around, head for the coop or the trees and screach the alarm noise and all h*** breaks loose in my yard as the hens and chicks run for cover and all of my roos stop dead where they are all eyes on the sky and looking around for whatever danger the guineas have seen (or have thought they'd seen). Its not only amusing to watch, but it also puts me up in the "whats goin on?" mode and I end up searching the sky and the fields with my eyes too! The last time they did this was last week because they'd seen a opposum. It heard all the rocus and took off!
They are a neat addition to our flock and yard and I truely enjoy them. They can be LOUD though, so if you have close neighbors they will not like them. Also, even if you clip them, they will wander about and not stay in a confined area for long (another thing your neighbors would not like). BUT, when done right (Ie: keeping them locked in the coop for a week or two before letting them out) they learn where "home" is and always return. Mine are often gone from view during the day, but I can hear them. They alwasy come back to the coop at night and when all the chickens are locked up, the guineas look down at me from their roost up high in the coop as if to say "See? Here we are!"