ok, simple analysis, traditionally in anime the thin line between rival and friend is often toyed with, u can see this in tons of other anime, Sasuke and Naruto start out as enemies, but Sasuke is first to respect Naruto when he recognizes that Naruto went thru the orphaned life that he did, later on Sasuke and Naruto become mutually respectful of each other after going through the treeclimbing training, as time goes on and more and more things go on with them, the chuunin exam and the like, Sasuke comes to appreciate just how tough Naruto really is and Naruto stops denying that Sasuke is stronger than him and admits hes a good rival, at that point i would say they are rivals that are friends, much like Kakashi and Gai, and they stay the same to date, Naruto says to Sasuke, i want to fight u, but he was 1)worried about him when he didnt show up, 2)worrying that he might have a hard time fighting Gaara, so he was telling him to be careful 3)throwing down the gauntlet...all that in just that short sentence, and Sasuke when he responds was saying 1)good job beating neji, i want to fight u to see how strong u've gotten 2) saying, i will win and kick ur ass and finally 3) dont worry about me

if u really look past what they say and look to how they say it and when they say it and the kind of people they are, u can pretty much figure out that this is what they're saying, sasuke or naruto would never ever ever say, hey man i was so worried about u wtf were u doing, or hey man be careful, this guy is tough i dont want anything happen to u, its a mutual friendship, mutual respect and a mutual understanding, when they say things to each other they realize what each other are saying because they're so similar to each other, thats why i think theyre good friends that compete out of respect

the 2 boy 1 girl thing has been brought up before, not all the groups have that but a lot do, but thats also how it would naturally fall out if u think about it, they choose the genin by ranks/grades, so u have a high rank kid with the lowest rank, then theres a mid-level one with good grades but poor performance physically, as a ninja, the boys would have the highest scores because boys are born to be stronger and faster than girls, then usually if a person is gonna slack off and get horrible grades, it'd be a boy usually, so thats why theres the 2 boys, then theres a mid-level person, maybe someone whos smart but not strong or just plain mediocre, in which case u have a girl because by the ways they were trained they usuallyc ome out smart but physically weaker than the boys, therefore 2 guys 1 girl, there were a few groups tho that didnt have 2 boys 1 girl

also, about the clan revival, thats a good point, but he wants to kill his brother too, if he revives the clan first his brother might be after him, i hope he finds a girl stronger than sakura to breed with tho, i'd feel bad for the uchiha clan to have weak members like her lol, smart but weak