1. Re habits, you need to communicate this clearly and calmly over time and be flexible. Marriage is about adapting to situations that ppl are not comfortable with. He will also have comments about your habits. It’s about supporting each other. It should not be said in any way which is hurtful or abusive, but with respect.
2. He does not have to support his sister but it’s recommended as Islam says charity starts with Family. However it should not be at the expense of his immediate family
3. Meeting Family is important and part of marriage. One can not exclude Family in this partnership. This will only be resolved by clear and honest communication which happens not at times where he or you are stressed or angry, but at good times.
Don’t forget to ask Allah to help because it is only He who changes hearts