All I can say is tough love
your the mother I think you should make the ground rules as in if you stay here you have to work as well this guys needs couselling, you are being an awesome mother by showing you care and asking for help and I will never diss someone. Im 22, married with my second child even though I have an extreme temper I take it out like a civil person even though I come from the same background as your daughters boyfriend...
First off sit your daughter and her bf down and talk to them make rules that you seem are fair make sure you inform her bf that if he doesnt smarten up or if he dammages anymore property he will have to take responsibility forit call the cops not only has he dammaged property its domestic abuse. What if he decides he cant deal with the pressure of being a parent and hits ur daughter or grandson you need to stand up for your daughters safety (yes she will get mad at you) but you dont always get what you want in life.
What im writing right now is somethng my parents did yes I got pissy with them and told them I would never talk to them again but now me and my mother have the best relationship and I could never ask for more. If I was in your place this what I would do for rules
~make bf get a job and pay rent just even ask for 100$ (make him sign a leaseas well inculde a dammage liability so if he dammages anything he has to pay for it) he needs to grow up
~be strict with your daughter but dont stress her out too much no means no
~inforce rules you think are adequate
~dont play one against the other sit them down together and inform them or just to talk
~call the abuse home/group hom and see if you can get a cousellor or someone to come in once a week use all resources provided to you
~just remeber your an awesome mother and no matter what ur doing whats right for your child
if you need to talk pm me or send me an email I can help from personal expierence
wishing you best of luck
jess
~