I largely agree with you on all the major points. The main things I'd add are:
1. Its not just to create artificial drama, but specifically to stoke drama in a shrinking and increasingly inbred reader base. Part of the problem is that the publishers are *still* largely building their business model around extracting larger and larger revenue out of a smaller and smaller price insensitive fanbase, because who cares if you drive away borderline readers and make new reader entry even less appealing, if you can convince Mr Comic Book Guy to buy another 20 comic crossover at full price? Which works fine, from a ruthless business perspective, until your customers finally vanish entirely, from dying of old age if nothing else.
2. Sometimes stupid retcon storylines can have good uses later on. Like, the various Vision origin retcons are pretty stupid and unnecessarily convoluted. However, his awkward relationship with Wonder Man later on was the center of some good stories, like under Busiek. This is why when making movie adaptations, directors and screenwriters should focus on hitting the heart of the character concept while stripping away the cruft. . . but also look for different and better ways to incorporate the good elements that later resulted from that cruft.
3. I have mixed feelings about Wanda, Pietro, and Magneto. On one hand, the actual personal relationships between the Maximoffs and Magneto in later years were typically fine and interesting, in a "dysfunctional family" sense. On the other hand, being related to Magneto inevitably draws them closer to the X-Men story milieu, which has almost universally been bad. Granted, "this mutant character is much better on average when they appear in Avengers comics" is hardly unique to them. . .
