I can't disagree more with the idea that this storyline has been banal. I think this season was exactly what the show needed.
I've been a fan of Eureka since the beginning. The show has always been about the characters first and the story second (if at all). I won't claim that it was always perfect, but for the first two seasons it was still pretty good. The third "season" (both halves) was almost uniformly bad, especially with regards to characterization. Most of the characters were not only written terribly. Some were written almost completely the opposite of how they were (Allison, Jo); others were written so over the top as to be nonsensical (Fargo). It could have been forgiven if the story was any good, but the first half (Eva Thorne) was boring and meandering, and the second simply had almost no plot at all.
This season has been more in the spirit of first two seasons by far: consistent characterization (with growth!), a decent plot that tied into previous seasons, consistency and logic, and a mix of seriousness and silliness that served to temper each other rather than fight against each other.
Regarding Henry's wife: I think that they handled it perfectly. Henry had to give it a go to avoid tipping things off, but realized that it wasn't going to be possible and had to tell her. A sudden divorce (or what have you) would have tipped things off even more.
To the episode itself:
Overall I thought this episode was good. I could have done without so many repeat scenes from the first episodes (especially the Jo montage). I liked the subtle mention of destiny vs. free will when Grant tried to stop Allison from saving Barlowe, but she saved him anyway. I'm also very glad they didn't reset everything; that would have been too easy. I liked that the show didn't forget about Jo's reveal to Zane, and Henry's wife wasn't needed in the episode so I wasn't bothered by her absence. One big question I had was about Johnson & Johnson. It seemed a little too convenient to be a chance investment, so my thinking was that the woman was from the future.