It all sounds very, very familiar. I have four first readers - my writing group - who are the backbone of early drafts, and a few other excellent betas. Then Teresa. Then Sam. With Inish I had
@Boneman instead of Teresa - with much the same process followed.
I can't say how important it is to gel with your editor. There must be trust both ways - trust from me that it's right, trust from the editor that the author is able to make the changes. The relationship with Teresa is very important to me - right from when she first edited Abendau (and I'm focusing on it instead of Inish because it's the series, so the big work that has multiple arcs etc).
As those who've read Abendau's Heir know, there're some tough themes in it, and I wanted to get those right. I wanted to present torture as non-gratuitous and put the focus on the victim rather than the gory actions. But I also didn't want the victim to be easily cast aside, or to be subsumed by the position of weakness they were in - hence why my protagonist is the victim (and we're not talking the usual chuck-everything-at-the-poor-chap-and-watch-him-get-over-it sort of ordeal). Teresa grasped why it was important to me. She understood what I was trying to do and, despite being no fan of such scenes (as she's mentioned in a few threads over the years) understood that the book needed them. So she trusted me. And, again, with the ending. I've had a fair few comments saying people don't like the ending of AH and find it a little gratuitous, in terms of cheap impact. Teresa simply told me that she assumed I had a good reason for it, and that it would be reflected in the later books. Now, apart from the shear panic of checking it actually was, I was glad - because there is a good reason for it, and it forms part of the central premise for later books, and part of the MC's arc.
But I also have to trust back. Being asked to slow the opening and insert extra scenes took me aback - but I did it, and the book is much the better for it.
And, yes, waiting for the notes back is terrifying. And then I always read them and go, yes, I can do that.
I've been lucky to work with the editors I have - long after I had hired Boneman, I was still going back with questions. Even at the very end, two days before I sent Inish for formatting, whilst poor Boneman was on his hols, he came back to me on a scene query.
So, if you're ever lucky enough to work with an editor towards publication, find one you mesh with if you can.