This is great and the list makes sense.
To Point 7 from @NicholasKoch changing from a MY to a NMY could be dangerous if the advancements they earned are removed, what happens when they then want to transfer to a Troop that also uses TT then if all of their achievements have been removed they are gone from TT.
If these NMY are not listed on the (Patrol, Unit, Den, Troop) page please make sure there is an easy way to view them, perhaps the Quick Nav, Members NMY broken out like Adults.
From a BSA Troop or Pack perspective I can’t think of anything else that would be needed.
Hi @dave ,
Would NMY’s be entered into TT manually/ individually? Right now, we download all of our member information directly from AHG. Maybe parents could enter their NMY’s info, and a leader could approve it.
#4 - I can see when a NMY would want to earn awards, if there were a custom award that the troop was making available to all participants/ attendees. I have been known to use TT to keep track of patches for adults. 
#7 - I agree that you might want to convert a member youth to NMY, as someone else pointed out.
#8 - For inviting NMY to events, I think you would want to be able to associate the NMY with their siblings’ units. E.g., if the Tenderheart families are having a family event, you would want to be able to invite only the Tenderhearts’ siblings, and not have to sift through the other units’ siblings.
Also, one NMY might be associated with multiple units, e.g., if they have 1 Tenderheart sibling and 1 Explorer sibling, you would want to invite them to both units’ events. (For that matter, you might want to be able to invite the registered Tenderheart to the Explorers’ family event, too, and we don’t have a way to do that either…)
But maybe this isn’t the direction you are going.
I can see the situation arise in which I don’t want to invite all the NMY’s, just the ones affiliated with the intended unit.
Good luck with this! Sounds like a can of worms!