I'm assuming Ted gave Michael upgrades for Skeets at somepoint. We don't know what they've been going prior to seeing them in "Argo". Remember that this is Q taking elements and concepts from the series and incorporating, and expanding upon them with the freedom he has in the comic book format. He won't have time to explain everything. Or perhaps he will in a side-story. I'm guessing Skeets is appearing as his usual self because Q basically has the freedom now to do that.
Imra doesn't look at all like Alexz Johnson but that surprisingly doesn't bother me. Most of the Legion look exactly like their comic book counter parts, Rokk and Garth kind of resemble their actors to a degree.
Why would Clark have memories that haven't taken place yet? For him? He has technically skipped anything. He's been time displaced. Like the type of travel we see in "Doctor Who". Besides which as I pointed out earlier, he will most likely return to the point of time where he was first taken from. So no time will have passed.