2 i think
*NO SPOILERS*Yes. Many people mistake Kingdom Hearts Birth By Sleep for Kingdom Hearts III. Kingdom Hearts Birth By Sleep is a prequel to the first Kingdom Hearts explaining Sora's past and focusing on three new protagonists: Terra Aqua and Ven. This is commonly referred to as Kingdom Hearts 3, because of the secret video trailer at the end of Kingdom Hearts II. Kingdom Hearts III is not officially started yet, but Tetsuya Nomura has stated in interviews that Kingdom Hearts III will focus on Sora once again, saying that "...Sora will remain the hero until the end." He also said that many more games will come after Kingdom Hearts III, so fear not.
2 games Kingdom Hearts 2 and Kingdom Hearts 358/2 Days
sora only has one keyblade, The kingdom key. the reason his keyblade changes is because of the key chains he attaches to it
sora as many keyblades but the first one he ever gets in both kingdom hearts 1 and 2 is the Kingdom Key it's the weakest, most basic keyblade in the game.
3 if you count Kingdom Hearts Re:Chain of Memories
Roxas is considered to be in 2 of the Kingdom Hearts games. He is the main character in the beginning of Kingdom Hearts 2 and then he is the character you play as in Story Mode in Kingdom Hearts 358/2 days.
If you are talking about Drive Forms, then Sora has Valor, Wisdom, Master, Anti, Normal, and Final Form, which equals up to 6 forms.
6: Sora, Kaira, Saix, Luxor, Xemmas, and Ansem.
Two kingdom hearts 358\2 days and Kingdom Hearts Re:Codded - Not counting the Kingdom hearts Codded that's not for ds.
If you mean after Birth By Sleep, the from what I know, yes, thankfully. :3 I read an article about Kingdom Hearts and the Square Enix is creating more new games, Kingdom Hearts III and another, which many might not know about, Kingdom Hearts 3D Dream Drop Distance. DDD will on the Nintendo 3DS which will revolve around Sora and Riku. KHIII is on the back burner because Normura and SE are more focused on DDD. Hope that helps!
7
That's easy, Sora has many enemies like Organization 13, xemnas, heartless, and nobodies. There's even more when he travels to different worlds.