Ever since he became an assassin, Floyd Lawton kills whoever he's contracted to kill. Or did, back when he was a villain.
Does he still kill people in SUICIDE SQUAD?
As it so happens, he has, several times, been paid not to kill Batman, but someone else, because, you know, getting paid to kill someone and failing all the time starts to look suspicious. If you think the only Batman villains or the only ones who can pose a threat are the characters that try to kill Batman...I don't know what to say to that...Besides:
Batman isn't Batman to protect himself. He's Batman to protect other people. The threat of harm to himself, in his mind, should pale in comparison to the harm that can be done to others.
That Deadshot was introduced as a supervillain is NOT inconsequential in the least. It is half the reason he ended up with the SUICIDE SQUAD, where he has flourished. If we are to honor the character, that element must remain intact somewhere. Now, if they make a SUICIDE SQUAD movie, and want to show him reformed/reforming and hint at or show a villainous past, fine. But this is a Batman movie, and should he end up in this Batman movie, he will likely need to be portrayed as a villain, not an ally or a wishy washy fellow in the middle, or a member of the Suicide Squad.
Let's say Deadshot is set to appear in the next Batman movie. Cool? Okay, so how do you explain why Floyd (a man with nigh-perfect aim) never shoots Batman in the head 0.5 seconds into the fight?
Batman altered his gunsights.
Seriously.
It's faithful to the mythology.
But really...obviously, because he likes the chase. He likes the challenge. Similar to The Joker, though it's a less overtly psychological approach.
You don't think people want Deadshot to be one of the main villains or something, do you?
Despite recent rumors, I don't think that's likely to happen. And...here's a CRAZY idea.
Deadshot is a dead shot normally...but he is not, in fact, superhuman. Like Batman, he is human, and can miss when he shoots, as people sometimes do.
But how do they do it in a 2 hour movie, where events like that are naturally decompressed and reflected on? Let's say that Strange hires Floyd to kill Batman. What does Lawton say when Hugo asks him why he doesn't just shoot Bats in the face?
"I enjoy the challenge, Huges. Step off or I'll shoot YOU in the face"
(I don't Strange would/should hire Deadshot. More of a mob or League of Assassins thing, methinks).
Either Deadshot doesn't want Batman dead (immediately de-fanging him as a threat to Batman), or he actually is trying to kill Batman, but still keeps missing his shots.
It's entirely possible that angle could be used, but the audience doesn't need to know that. Or maybe Deadshot hits him...but Batman survives it through sheer pluck and moxie, and it becomes a gentleman's game, a duel of sorts.
Now if Deadshot unintentionally misses his shots, what's the difference between him and just another crook with a gun?
Because he's still amazingly cool, and he's incredibly capable.