I think it's normal for the house to bother you. That was something you and he worked toward for a long time and now OW gets to enjoy it. Fuck her and fuck him.
At the same time, you are on the right track in thinking that all of his money and things are just empty. He has no center, no core, and no amount of money will change that.
My IC once asked me how I defined success. I told her that I thought I would be successful if a handful of people missed me when I'm gone from this world. If I made an impact and my family and close friends had good, loving memories of me. Money didn't come into the equation.
If you define success in a similar way, it's easy to see that your exWH is not successful by any stretch of the imagination. He tossed everyone away, including his mother, daughter, and best friend. Who will be there for him in the end? Is OW gonna be there when he's old and sick and runs through his money? He better hope so since there is no one else.
My exWH did the same thing. He threw away everyone and now has virtually nothing. OW is still in the picture, but they certainly has no happily ever after lifestyle. Meanwhile, he's lost the respect of his colleagues, family and friends. And, as far as our kids go, they are little but already see that they are not his first priority. These days, that is reserved for OW and alcohol.
Anyway, my point is that he's got nothing. Regardless of what he can show in a bank account, tax return or real estate portfolio. He has and always will have nothing because of who he is on the inside.
BW - me
ExWH - "that one"
D - 2011
You get what you put in, and people get what they deserve.
Hard as it may be, try to never give the OP any of your power or head space.