Hawkeye can be a great movie, if you make in the lines of The Bourne Identity.
Think about it.
Clinton "Clint" Francis Barton was a criminal, a very skilled thief, that, after being defeated by Iron Man, turned into heroism.
In the Ultimate Universe, Clint Barton is a black ops operative of the Ultimates.
Why don´t combine both?
Start off with the criminal angle, a master thief, a mercenary to the higher bidder, but with a heart of gold, that carefully plans his missions and chooses his employers.
That gives a reason for Clint to have the codename, to dress up, and to choose the bow and arrow as weapons.
And, with the all criminal angle, it makes sense to keep his flamboyant and "not play by the rules" personality
Then, turn his world upside down...