Great analysis, as usual. It's nice to see all of that development laid out in one place.
For me, the proof of Jack and Ianto's sexual relationship pre-Cyberwoman is still Owen's line in CJH. Ianto says that Jack needs him, and Owen says, "In your Dreams...your sad wet dreams, when you were his part time shag." We know that not much time passed over the course of the first season. Six to nine months, at most. Since we can assume that Jack and Ianto had no break in their relationship between TKKS and EW, it makes more sense that Owen was referring to a period before TKKS, and that he wasn't aware that they had resumed their shagging. It also makes much more sense for that period to have occurred before the metal girlfriend was introduced to the equation. So whether they were shagging or not, Owen assumed that they were, and therefore the producers saw it as possible, if not probable.
no subject
For me, the proof of Jack and Ianto's sexual relationship pre-Cyberwoman is still Owen's line in CJH. Ianto says that Jack needs him, and Owen says, "In your Dreams...your sad wet dreams, when you were his part time shag." We know that not much time passed over the course of the first season. Six to nine months, at most. Since we can assume that Jack and Ianto had no break in their relationship between TKKS and EW, it makes more sense that Owen was referring to a period before TKKS, and that he wasn't aware that they had resumed their shagging. It also makes much more sense for that period to have occurred before the metal girlfriend was introduced to the equation. So whether they were shagging or not, Owen assumed that they were, and therefore the producers saw it as possible, if not probable.