I have definitely experienced some of these in the past when I was more naïve and gullible, and it's important to keep a lookout for them in order to avoid what could be abusive or controlling situations, or just dating an utter belend or a player !
I'd say:
ANY form of violence whatsoever
Racism
Homophobia
Sexism and what women are 'expected to do'
Very tight with money-keeps receipts for what you owe him and makes sure things are split to the last penny
Every ex is a 'crazy psycho'
Out with mates 'getting pissed' every weekend unless an 18 year old student.
History of cheating/leaving partners for someone else
'one of the lads' very loutish and lairy
Rude towards wait staff and shop assistants
Massive mummy's boy
Overly needy- texting you again if you haven't replied as quickly as he would like, i.e. 10 minutes
You met online and they are 'leaving to go travelling soon' (unless you want a casual fling)
Pushy about sex/puts pressure on you
Aggressive when drunk
Wants to meet your kids/for you to meet his kids very early on
Proven liar
Stroppy if you go out with your friends
You feel like you're walking on eggshells
'not sure about you' after several months
'too busy' to see you for weeks
Feel free to add any others !