It's over for you but obviously he has unfinished business. Whether it's sinister or pathetic, I can't say, but I've heard of it happening after a break up, in fact have done it myself, but only once, not repeatedly.
How classic that he's lying to your daughter, but doesn't cover his tracks enough to conceal his drinking.
I'm not sure you can do anything much about him driving past, but you could talk to a lawyer, the police or a DV line about it and see if you have any options. Do you think making your separation official legally would give him the message that it's permanent?
Why is his behaviour contradictory and illogical? The Facebook rant was probably pride driven, but of course he wants to come home. It must be horrible boarding with relative strangers and not having freedom to drink as much as he wants.