So you would be more okay with starting with Superman with a different directory? If so, any preferences?
Me, I'm okay with him doing a solo film. I mean, you could take all of Rocket's backstory scenes from Guardians 3 and remove everything else and the film would still hit me in the feels like a sack of bricks. So I have optimism as I see this film tomorrow night.
Plus, if Gunn was doing to do a Justice movie like you said, then I would have made it the actual Justice League International, whose most iconic run in the late 80's to early 00's was very wacky and comedic. Have Guy Gardener, Hawkgirl, Maxwell Lord, and maybe Mr. Terrific (he's more well known for his time in the Justice Society of America run by Geoff Johns, James Robinson, and a few others, but he could be reworked into the JLI).
Then add Booster Gold (who is getting his own TV series eventually), Ted Kord/Blue Beetle (they're supposed to introduce Jaime Reyes in this verse with an animated series eventually, but they could still keep Ted alive and active by having him still make new tech by visiting Jaime and working with him on the Beetle scarab), and Fire and Ice. I'd think that group would be a fun dynamic and Gunn could nail it.
I was worried if they did add Ice, well, her and Guy Gardener being a couple is a major aspect of their characters (she's like the one person he'll generally treat with kindness, though he occasionally lets his more immature side show with her), and with Nathan Fillion playing Guy, I was like, "man, they're going to have make Ice much older, that'll be weird". But actually I checked and Fillion is 54, they could have Ice played by someone in their mid to late 30's and it would be fine.
Still weirded out that Hal Jordan in the Lanterns show will be played by Kyle Chandler who is 59. I think people are convinced they're definitely going to kill him off like the 90's storyline, but I hope not, too many big Green Lantern stories have Hal as a major player, and you have his friendships with Oliver Queen/Green Arrow and Barry/Allen/Flash (unless they just start with Wally West), his long feud with Sinestro who is the iconic Green Lantern villain, and his relationship with Carol Ferris.
If they do kill off Hal, I could hope the Rebirth storyline then gets adapted later and he is revived in a somewhat younger body played by an actor who could pass for a younger-looking Kyle Chandler.
Plus, when Hal was dead, he became a new incarnation of The Spectre, a divine entity who passes judgment on corrupt humans and other beings, though Hal tries to change this mission from judgment to offering possible redemption. A well done Spectre film could rock, with some level of horror elements.
Anyway, sorry for the Green Lantern tangent there.