Working out consequences of science-fictional ideas

I have a pet sci-fi setting I use as a handy platform to play with various ideas, such as figuring out what some of the likely consequences would be of relatively easy access to orbit, or applying ‘Avatar’ remote-control techniques to live people. One question that recently occurred to me is, “Can you have a crossover with another fictional setting, without breaking any known laws of physics?”

The setting includes super-Siris, conversational engines good enough to fool an average, anthropomorphising person (but not true GAIs, since the consequences of /those/ would derail every other hypothetical in the setting). Throw in some full-sensory VR, and it seems plausible for someone to not only exchange email with a conversation-bot Captain Kirk, but get shown to the captain’s quarters… And, depending on what the setting is, there are various rationales to explain how the VR-naut happens to be visiting that ‘universe’. With realistic robots, even ‘visits’ the other way could be arranged: “Have a real Spider-Man at your birthday party!”

The Rule 34 potential is obvious; but I’m trying to come up with what /other/ consequences would result from such tech. How would marriages change? The labor force? Military simulations and operations?

How would /you/ go about thinking up interesting and/or useful extrapolations, for this idea in particular or for such ideas in general?