whether I'd feel different about the final scene (and the slight sense of artificiality in Garibaldi's WB cartoon fondness9 if it would have led to a Garibaldi/Delenn friendship

Or for that matter, I think it would have fit better for me if they'd e.g. been at a diplomatic function and the same thing had happened, or if one of them had unwisely been romantically interested in the other, and they'd always been a bit awkward afterward. I would like to see more of both of them: their similarities and differences contrast each other quite well, so a friendship would have been interesting too. But I think what bugged me about it (even in first watch) is that there didn't seem to be any reason for them to hang out together other than that they were both main characters (bridge crew DO have a reason to socialise mainly with bridge crew, but ambassadors and chiefs of security less so).

You make an excellent point about the cartoon -- I hadn't thought about WHY they did that, but for me, I thought it fit Garibaldi very well! :)

it's rather the opposite, since the person the device reacted to wasn't a reincarnated Valen but the one and only, in the flesh.

Yeah, that's about right. There's studiously never any actual evidence, which definitely suggests "there isn't any soul afterlife", but could also read "we left it ambiguous"