I'm not someone who read Secret Warriors, so I'm genuinely curious. Quake is obviously on the show and Slingshot apparently will be. Obviously, the show is also creating original characters, but who else do you want to see from the comics?
Just going off Wikipedia, there have been:
Current members
Nick Fury (codename: Motherf'in Sam Jackson)
Daisy Johnson (Quake)
Yo-Yo Rodriguez (Slingshot)
Jerry Sledge (Stonewall)
Eden Fesi (Manifold)
Former members
Sebastian Druid
J.T. James
Alexander Aaron (Phobos)
There are some rights issues. Of these characters, Stonewall is probably off limits since he was created for X-Men and part of Freedom Force for awhile (he's also complicated and stupid). Eden is cool. He's probably available, but his backstory isn't (he's a mutant who was trained by Gateway, also an X-Men character). The rest are likely available.
I'll wait before I give my thoughts since I'm less familiar with the characters.
That's the other Stonewall (Louis Hamilton), who was created for X-Men. The one on Secret Warriors is Jerry Sledge, son of Absorbing Man. His powers are also extremely similar to Creel's. So they could use him if they wanted, but I wonder how they'd introduce him, as him being Creel's son would make it so that Creel would need to have become a father at the age of 19 at the latest if they want Jerry to be a very young adult, which although definitely possible, might seem a bit young.
Yo-Yo has been confirmed about as much as it was confirmed that Spencer Treat Clark would play Phobos, so that isn't saying much. They did reference her dad Johnny Horton in season 1. In the comics she got her powers in a similar way to how Daisy got them (until retconned), namely through her the mutated DNA of her father who had been experimented on. Because of this, she could easily be an inhuman on the show.
I like Eden a lot, and hope to see him one day. Although his origin would indeed need to change completely.
Druid is not actually placed correctly as "former member", as he wasn't actually kicked off the team. That was just part of Fury's plan. I feel it would probably be better to introduce him around the time Doctor Strange comes out, as he's linked to that part of the universe a lot. I do feel like his personality from the comics might be a bit too similar to Joey's.
I don't really care for seeing James T. James, as his character and arc are too similar to Ward's, and we probably won't have a link to the Phantom Rider anyway.
Phobos would be really cool. They could probably have a season long subplot about him. Definitely more than with any of the others. I'm not sure if they'd want to introduce the Greek pantheon on tv though. But then again, they did introduce the inhumans.
From the other characters on the show Deathlok would be the obvious choice. If he gets on the team I really hope for another upgrade to his costume, and maybe a bit more personality too.
My biggest fears for the Secret Warriors on the show are that 1)it will have mostly inhumans, which would make the characters a bit too similar, imo. and 2) it will have a lot of original characters, which would really be a missed opportunity imo, as there are so many interesting characters they could choose from. With the inclusion of Lincoln and Joey (and maybe Alisha) it's not looking very good in this regard.
If they really wanted to include "original" characters, they might look at the other caterpillars, from team grey and team black. They barely have any established backstory, personality and canon, but at least they're sort of from the comics and related to the secret warriors. Or perhaps even some no-name participants of the 50 states initiative.
There are links to the character pages of all secret warriors and other caterpillars here:
http://marvel.wikia.com/wiki/Caterpillars_(Earth-616)
