In a way, Sasuke has two rivals. Naruto is his first, but that's mainly when Sasuke is still in the village and it's more of a friendly rivalry than anything bad, until the time just before Sasuke leaves, when he finds that he can't deal with the power than Naruto seems to have obtained. After their big battle, Sasuke stops considering Naruto as a rival. All through the series, Sasuke's biggest rival always has been Itachi; he is the one that Sasuke ultimately wants to train towards beating, and that is the reason that Sasuke leaves the village - he wants to become more powerful in order to be able to beat Itachi. After he beats Itachi, I don't know who he sees as a rival as I haven't read that far :3 But I do know that he changes his team's name from Team Snake to Team Hawk and is set on destroying the village. Sorry if the last part is wrong :]
An archrival is a particularly fierce or passionate rival.
Nemesis
joker
Blueto or Brutis
Best friend
Main competitor
Pisa
No
He doesn't have one.
Really good!
Sharingan
Suaskes (?) If you're talking about Naruto, Sasukes parents actually get killed by Itachi (Sasukes older brother)