...but are these purely speculative questions really good questions for this site?
My feeling that guidance comes from the type of answer that the question asks for. If the question is asking for quality answers worth reading and that fit within what's considered on-topic, then the question itself is probably on-topic and worth keeping around and answering.
Purely speculation questions may not be a good fit, but mine is not a speculative question! Gedankenexperimente are a recognized technique to get at underlying facts and phenomenon. Just for example I have at least two questions in Space SE that use the term explicitly (and one in Physics) and other have used the term as well.
A list of questions here that are by their nature thought experiments without explicitly saying so would be quite long. This is a reasonable, thoughtful and smart community; we can handle this.
For If the Earth spun clockwise, would Florida have still satisfied the requirements for the US launch center in the 1960's? I've written
Question: At the time of the build up of Cape Canaveral Space Force Station in the 1960's for the US space program, if the Earth rotated the opposite direction would the west coast of Florida have matched all of the constraints in terms of downrange safety for all inclinations the planners envisioned access to and provided ground tracks that allowed for tracking stations in friendly locations for the early crewed orbital missions, or would California have provided a location more suitable to their perceived needs for a space launch center at the time?
I feel that it's pretty clear this requires an answer based on facts. Now maybe it takes some time to round up those facts and so it's not easy to answer quickly, but the question is written carefully to dis-invite speculation.
On the comment
How deep down this speculative rabbit hole do we need to go? What if JFK had been an astronaut instead of president?
I've flagged it with the explanation
false flags placed strategically immediately below questions generate a baseless negative perception; had the commenter read past the title they would know this wasn't needed (and is no longer needed)
I think the continued discussion in comments makes it clear that an understanding of trajectories and ground tracks rather than politics are key to answering this question.