I'm not overly affectionate with my horses, but I do pat/whack/scratch... Gets them used to it, and some horses seem to feel "complete" when they do a good job with some kinda of affectionate gesture (some don't care). I definitely don't do treats, except on rare occasions, and not as a reward.
Granted, I don't go overboard and smack the s*** out of them like some folks you see, but I see nothing wrong with a decent pat occasionally.
.... My dad.... I could be working on the meanest, spoiledest, kickingest, brat of a horse, and it NEVER fails, at some point he will appear out of nowhere, directly behind the horse and WHACK, WHACK, WHACK seemingly as hard as he possibly can... And then proceed to roughly manhandle it in anyway possible. Never fails. And each time, the horses reaction is always:
and nothing more.
I'm always cringing for impact of hooves to skull.
And somehow, my dad gets away with it. Every time.
(Considering every other unimaginably insane, unsafe, and just at times stupid stuff he manages to get away with, I am absolutely amazed he's still alive. He's 70 now... And in those years I swear he has learned absolutely no common sense about anything, lol... But, I love him, and am always prepared in standby mode to doctor him up or take him to the ER)