if she fulfills her condition the house is Elaine's. Now it was nowhere mentioned that house have different conditions i guess.
I'm 90% sure her conditions are entirely based on MCs approval. There were allot of clues that point to that but this one is the biggest.
But that don't necessarily means she's going to screw you over. But it does mean that you are dependent upon each other.
In order to have a relationship with one of the girls, Monica, Jenna or Katie you have to forfeit your inherentance. No way around that so far, BUT if you agree that Elaine can have hers and you screw the Viper out of theirs Elaine will get all 13mill, and she has more or less promised that you will get some.
If you don't trust her however and you deny her, her portion. Then you will still get nothing.
The only way for you to Guarantee you get a cut is if you remove the girls. Let's say you do get Elaine permission to get a cut, and she betrays you. Well you didn't really loose anything you weren't already not getting and she looses Bella's love and trust for the rest of her life as well as yours. The only last two people she has close to her. Currently until we know who the Viper is I think Elaine’s plan is worth the risk.