My parents are flying CDG - KEF - YEG and back in a few weeks.

Iceland is in the Schengen zone, so returning from Canada to Europe, I understand they would have to clear passport control. I think European/Schengen countries also require an exit stamp (there are none in my passport because I'm a Canadian/EU citizen, plus I just can't remember). Two questions:

1. Will they have to go through passport control at KEF on the France - Canada leg of the trip as well?
2. Could anyone give me some practical pointers (where to line up, what route to follow, for example colour coded lanes - green/blue/etc.), simple enough that I can pass on to my folks who are elderly and speak hardly any English.

They hold EU passports, if that's relevant.

Also, there appear to be 2 Icelandair flights from CDG to KEF leaving 10 minutes apart, at 14:00 and 14:10. What's up with that??? Flightaware shows the earlier flight, on which they are, actually having a worse on-time record of late, including a 3-hour delay a couple of days ago. I understand that the Icelandair model is such that there are 1-2 hour connection times by design, and that planes would wait a bit to make sure passengers make their connections. So a third question, if my folks end up on a flight that's delayed 3 hours, what would Icelandair do for them in Reykjavik? Hotel/meal? Or with their shift to a low(er)-cost airline will mom and pops be SOL?

Thanks