I could definitely be wrong but I think Makar, Fabbro, Foote, and Lind are all too old to play

Makar Is for sure. Found a hockey writers article saying best case scenario everyone is available for Team Canada roster

Forwards
Alex Formenton-Robert Thomas-Liam Foudy/Max Comtois
Barrett Hayton-Gabe Vilardi-Owen Tippett
Michael Rasmussen-Cody Glass-Nick Suzuki
Jaret Anderson-Dolan-Ty Dellandrea-Jack Studnicka

Alexis Lafrenière/Liam Foudy

Defencemen
Ty Smith-Noah Dobson
Pierre-Olivier Joseph-Evan Bouchard
Jared McIsaac-Calen Addison/Jet Woo
Bowen Byram

Goaltenders
Michael DiPietro
Olivier Rodrigue

Age limit is 20 years old Makar, Fabbro, Lind are all 20. Foote is 19.

How about Josh Brook who is right D and has 21 points in 15 games and a plus 6. He could be powerplay general.

Incorrect, they cant play int he tournament. Foote turns 20 in December before the tourney starts
The age rules state that the the player has his 20th birthday in the year of the tournament's ending, which is 2019. All these guys have had their 20th birthday in 2018. They are all 98 born, anyone with a 99 birthday can play.

I'd be pretty surprised if someone other than Merkley was running the PP as a right shot D.