They are extremely friendly! I have one that hops onto my finger anytime I offer it to him and my fiance has one that loves to sit on his shoulder and cuddle in his hair, lol. The boys tend to be more outgoing and the girls are usually a little timid, but sweet.
2 bantam roos is very tricky. Most will not tolerate another roo around their hens and can fight viciously, and they do not stop once started. You might be able to get 2 to live together if they are raised together and both have plenty of hens, but it is a crap shoot. A bantam roo has a better chance of getting along with a large fowl roo than another bantam, depending on the large roo, too.
2 roos won't necessarily give more protection, they are to small for doing much against a predator, but more for sounding off and getting everyone headed for cover. 1 should be enough for that, they really don't miss much! They are super inquisitive and react to any new sound or object in their area. Hope this helps!