Lio, your post was pretty epic in every way, and really thoroughly combed through all that we've been presented Shamy-wise since the last season finale and what those details implicate.
I am nowhere near the devastation of some shippers (because this really doesn't have to end badly and could be a brilliant catalyst for the opposite), but I have to agree that the key narrative flaw of all of this is that we just don't see...I was about to say Amy push back, but that wouldn't be fair. Unlike some people, I think we've seen her assert herself and pick her battles, and while she is not as demanding as she once was, that makes sense, since loving someone can soften your edges. What we need to see (as you mentioned) is more narrative from Amy's perspective. Even if she behaves the exact same way, we just need to experience her side of things; this relationship isn't "The Sheldon Show." They are the SHAMY. Beyond this, however, the one thing that I wish I could demand is something from Sheldon that blatantly, verbally, clearly communicates that he simply can't live without Amy. I have not doubt he loves her (and I'm pretty sure he doesn't doubt it either, which is what really scares him), but Amy has flickering doubts because being INSIDE a relationship is the most vulnerable position. I want to be optimistic and say that's exactly how all this is going to end, but TPTB seem married to the idea that Sheldon is evasive of his emotions and everyone has to just deduce how he feels about things and be content with that. Except, he's effusive about how he feels about his mom. He clearly was enamored with Professor Proton. He can tell Leonard how much he loves him and depends on him. Why does that come to a screeching halt when it comes to Amy?
Part of me knows that his relationship with Amy has an intensity and intimacy to it that transcends all of those other relationships, and someone with his limited emotional skill set would naturally be intimidated by how present he has to be emotionally. But at some point, shouldn't he just runneth over? How can he stand to be so reticent? Yes, he told Penny "First of all, I'm very fond of Amy," (one of my favorite Shamy moments ever). He also told Amy, "What we have is very intimate." She got the drunken "Isn't she great?" butt-slap. But these statements are couched in very conservative language (and booze) and Amy didn't hear the best one. For me, personally, it's getting to the point of intolerable that, for example when he got back from the birth of Missy's baby, he couldn't just say, "I missed you, too." Would that have killed anybody?
When he gets back from wherever he's going (because, duh, he's coming back) I need a BIG MOMENT. An "I love you" may be too much to aspire for (and maybe just too much) but can he acknowledge that he missed her, or something? I would take a sleepy-eyed kiss (I'm sure we all would). But, as Lio pointed out, a change is gonna come. The reality is, his days of living with Leonard are numbered. His job is only going to wait for him for so long (thank God it's summertime, though research professors don't get the summer off, so...TV-land). The comic book store is decidedly gone and not coming back any time soon. These realities are unavoidable and all the tantrums, contractual agreements, emotional bullying, and train rides to Timbuktu in the world are not going to change them. So, there will necessarily come a moment when he has to just...deal with it. What I ABSOLUTELY don't want is for Amy's part of this ("My girlfriend loves me so much that she wants to move in with me") to get subjugated to those other epiphanies. I know that his desertion is a result of being hit with a...crapstorm (what's the profanity policy at this board?), but I think it would be unfair (if not disrespectful) to Amy's character and their relationship if it was not given the priority among his reasons for returning. Honestly, if it weren't for her, he could leave if he wanted to. It would be a bit reckless, but it would still be a personal choice. Leaving her like that, however, would be heartless and wrong.
And he doesn't want to leave Amy. To his credit, he made it clear that they are still together, based on his call. But what good is a relationship that so unstable? TPTB could go the route that Amy goes after him, or she gives him an ultimatum, or she (ugh) begs him to come home. But I think it's unfair that he gets to live with the emotional security of knowing that, no matter what, he has a woman that loves him waiting for him somewhere and that he has access to her whenever he needs, but she lives with the perpetual fear that if she just hugs him too hard, or makes his spaghetti wrong, or glances at a baby stroller in Target she may lose him altogether.
That has to be fixed. Soon.