Well, if you start boosting their stats more, I think they'll definitely be undercosted. Making them Unique helps offset the cost difference a little. But, take Sev for instance. Only 2 points more than the old version. But he gains 30 more HP, 1 Defense, Katarn Armor, and Sniper. That's a big boost for 2 points. Granted, I'd say the old RCs are a little under powered compared to today's pieces anyways, so it's probably OK.
I would be worried about someone runinng the RCTS with these guys though. Shields 2 on top of 60 HP could be REALLY frustrating.
What happened to Scorch's Grenades 10?
I really like Shaped Charge. The wording may need a tad of tweaking. Instead of "Designate 1 adjacent wall segment as open" (since "open" really isn't a defined word in the SWM game), you might say something more like "Remove wall terrain line along 1 square". I don't know, not sure I like that either. Could maybe make it more like Dark Woman's ability...hmm....how about: "Replaces turn: allied characters, including Scorch, ignore walls adjacent to this character and all squares adjacent to this character provide cover until the end of his next turn."
I would definitely try to add a little flavor to the Omega guys though. They aren't just cookiee cutter copies of Delta squad. Should have some similar abilities, but not completely. I.e., both Fi and Atin share Sniper duties throughout the book series. Fi is more of the communications person, but Atin is more of the slicer, so they kind of split Fixer's duties there. Darman and Scorch are pretty similar I guess, as are Boss/Niner. It's really Fi and Atin that don't match up with Sev and Fixer quite the same.