This might not be right, but I think it could be close. Are you:
A pirate (More so, Jack sparrow from The Pirates of the Caribbean)
Crazy or not, you know who I am,
Most people know about pirates
I can use a knife, not just for jam.
They often use knives and swords as weapons while fighting
Death is nothing new to me.
Pirates are often in fights to the death with others
You know the glasses that help me see.
Possibly referring to a spy glass which helps them see longer distances on sea
Rogue or not, I've saved the world.
Jack has fought against Davy Jones and Hector Barbossa to protect the world!
I salute when the flag is unfurled.
He will salute his flag and also a possible reference to honoring the pirate code.
The future I thought I once knew,
Jack thought he was always an evil pirate
Instead honesty became my main view.
After meeting with Will Turner and Elizabeth Swann his views change to a becoming a better more honest pirate (for as far as pirating can go)
Is it day or night, light or dark,
This could reference being inside a boat you can't tell the time of day. Also a possible small reference to the use of an eye patch which helps in literal light and dark situations.
Tell me who I am, and something cool that I park.
Jack Sparrow, and his ship the Black Perl!
Also the title "Come sail away"
A reference to him and his crew to sail away in his ship.