This will be a helpful piece of evidence for future apologists when the “Joseph Smith as allegorical and not historical” phase of enlightenment takes off.
I don’t believe they put a cross on the Rome temple. There was an early animated computer model that had a subtle cross in the main doors, but I don’t believe that made it into the actual completion.
No, but I also couldn’t name a single “non-believer” that’s gone on Mormon Stories since his ex-communication. I don’t believe Dehlin is particularly looking for “believers” on Mormon Stories. As there’s a rather wide swath of “believers” and comparatively few (singular?) people making invitations for Mormon Stories appearances, a “boycott” may be easier to organize on one end of that equation than the other.
Likely the same reason I would offer many opportunities to my children for many things. If I were to find out that they’d eventually hate me or not have a relationship with me or would reject what we offer as parents, we would still make those same things available irrespective of whether they’d later appreciate it or not.