No, he does not die, meaning that he is not dead. He's even a character in Kingdom Hearts. Very rarely (except for Aerith) are the Final Fantasy characters that show up in Kingdom Hearts dead in the Final Fantasy games. I think that Aerith is the only one who is dead in Final Fantasy, but is alive in Kingdom Hearts.
Yes, Seifer Almasy and Squall Leonheart grew up in the same orphanage as each other, and though they forgot this due to the effect of using Guardian Forces, they also knew each other at Balamb Garden, where they were rivals in the art of gunblade fighting.
Leon is a side character that appears in most of the Kingdom Hearts games. His true identity is Squall Leonheart, the main character from Final Fantasy VIII. In the first Kingdom Hearts game Yuffie (another side character, originating from Final Fantasy VII) calls him Squall, but is quickly rebuffed, as Leon tells her he no longer goes by that name. It is not explained why, however.
A squall is a windstorm. An example sentence would be: Please be careful not to get stuck in the squall.
Squall Charlson is 5' 11".
Squall Leonhart was created in 1999.
Piano Squall was born in 1983.
Squall has brown hair.
White Squall was released on 02/02/1996.
The Production Budget for White Squall was $38,000,000.
That would be a squall.
The duration of White Squall - film - is 2.15 hours.
I would say Squall Leonhart or Seifer