I understand that feeling of wanting to "do" more, when sometimes doing less is actually more. In terms of him getting angry and blaming, I would say revisit the validation threads for ideas. It is a good way to let him know that you are listening and care about what he says, without necessarily agreeing or taking the blame. It's a good skill to have in any R.
I don't know what else to tell you about why he is investing in expensive house projects. I don't think it is an indicator that he will come back, as much as I don't think it's an indicator that he won't. Sometimes it is hard to accept that we just don't know why. You don't though. He may not even know. My H certainly gave off signs that he would return and it wasn't even his intention. If someone had asked him at the time, "are you doing this because you plan on returning home?" I don't think he would have known how to answer. He probably would have said "no" just to save face.
If you read all of Cadet's HW, you will see that they speak in absolute negatives because they are also scared. Remember to believe none of what he says and half of what he does. The more sure they seem, the more we believe it is true. That is incorrect. There were times I would press H for answers, "What are we doing here? What about the house? Or the kids? When are we getting D?" I would really test him. The more I did this, the more I was met with "I told you we are done and it's over." I think forcing this out of him also aided in him staying away longer.
It wasn't actually true tho. He was hurt and confused too. He felt that he had made his decision though and was also showing face and protecting his ego. I didn't learn any of this until after he came back of course. So I would say if you press him for answers, it may only hurt you more. Can you accept that there is a chance that he is as hurting and confused as you are? And maybe be is hiding that so well because he is a man that just walked out on his family and is afraid he made the wrong choice, so guilt and pride may further cloud his judgements? I don't know this but perhaps it's possible?
I know it must hurt they are taking the family vacay without you. I did this with my kids and it was hard for me and for H being left out. All in all though, the benefits of time, space away, and detachment seem like a great opportunity for all of you. Maybe this is what you all need?
Hang in there! Blu
“Forgiveness liberates the soul. It removes fear. That is why it is such a powerful weapon.” – Nelson Mandela