Some of the customs are not all anti islamic persay and some are!! In your situation try to limit the haram as much as possible. I have seen even relegious brother cowering to parents emotional black mail!! As for seperation, if you can't enforce physical barriar then atleast keep it segrgrated. My parents weren't happy about many things but beng stubborn did the job. The main thing is marriage is not a funeral and is a happy occasion for both families so do your best to limit haram . Do not go overboard with islamic thing. There is appropriate place for these things. Perhaps a 5 minutes reminder in english about virtues of marriage. Allahualam