Hi there, and welcome to the forum. I am relatively new here, too, but not new to non-monogamy. In your story there are a few points that I can easily relate to. Here are some parts of my journey that came to my mind when reading your story:
Firstly, the mono-poly part. Though my relationship with my husband (CJ) never was monogamous, there has been a lot of discussion about it, and he has assumed many things that never were said. He was new to non-monogamy when we met, but knew all too well all sides of the mono cheating stuff. Our relationship was open from the very beginning, and we were both active on the dating scene and seeing other people as well. As the relationship evolved to something more and more meaningful, he assumed that we won't be open any more; that the "being open" was a kind of "try before you buy" thing. So I had to make sure he understood it really is going to be open.
The next crisis was after we got married, though luckily only on a discussions level. That was a second time he assumed that the openness was all done with; without us ever having a discussion about it. Anyway, we managed to talk through that as well. I will always remember the horrible shock I went through as I realised his assumptions and thought that our marriage had been built on false premises altogether...
Each of my short time relationships have been a crisis, as well. Nothing huge, but a lot of communication and jealousy management has been required. Now as I have found someone I wish will stay in my life (my lover Mark), there is a new crisis: our marriage moving from "open" state to "polyship" state. It has required this time less talk and more action to confirm CJ that he will not be forgotten or loved less even though I have an OSO now. Also, I have been proceeding in my relationship with Mark in a pace that CJ can cope with.
So I do not have experience of changing from mono to poly, but have sure had my share of changes in the status of my relationships. No, I do not think there is anything morally wrong about you continuing your discussions with your wife about the possible change in your marriage.
Secondly, the online relationship changing to a LDR - though in my case the distance is not that long. We had an online relationship for several months before the first date, and it never was sure that we will meet IRL though the meeting was easy enough to arrange for the practical reasons. I just did not know if and when my husband would be ready for any of my possible new relationships. But as the "miracle" happened and I met Mark, it felt immediately like we had known each other for ages... Simple and easy. So far the change has been smooth and natural, no fuss whatsoever.
Hope it was helpful, in any way. Feel free to ask more either here or through PM.