You say you told your boyfriend off because "she" was rude and disrespectful to him.You turned around and repeated her behavior.I dunno if you see that ? It does not seem as if your issue is that he is being taken advantage of or mistreated,rather that he hasn't handled things as you wanted him to.
As far as her being rude and disrespectful to him , it is up to him to deal with her. If she is rude and disrespectful to you though,you can draw the line.
You say he is your boyfriend,so I wonder whose home it is?You said "we cannot and should not support her" is the money being spent from your paycheck? You can control that part.
You say he has no back bone and cannot face up to what he does wrong.Dang! do you actually "say" that ?You say you are "stuck" with him because you are dependent on him for $ ???????? I am not thinking why are You with HIM...more like ...dam this poor guy is getting it from every angle.
An intimate relationship should be loving and feel like "coming home to a hug" if at all possible.As far as his priority....wow...I would have to say his priority is him first...all others second....he needs to feel loved ,respected,and valued.He is a man. If you respect him and are loving he will feel empowered to behave like one...yes?
He is not abusive...not controlling...and financially supporting you.You should be grateful for that.And do whatever you can to make him know he is appreciated and cause him to smile...cause in the end,between the two of you,he is gunna have an ulcer or whatever...anyway that is the way I feel about what I read ....Wolfsong >.<