Quick question regarding Mutant Schticks:
Unless I'm missing something, the Gene Freak is the only archetype that has access to Mutant Schticks. How would a character acquire a mutant schtick that isn't in the Gene Freak's "Awesoming Up" list (i.e. Berserk Rage, Blinkshifter, etc.)? Obviously, the GM could approve you to taking any schtick you wanted, but I'm curious if there's a way to acquire those schticks without hand waving/house ruling anything.
Not really. Those schticks are also really useful for creating GMCs and other antagonists. As you say, you can always modify an archetype with different mutant powers, but we didn't playtest every possible combo so tread carefully.
If a non-Mutant wanted to pick up Mutant schticks, I'd probably work out some sort of sidequest that involves hanging out near a blast crater or exploring the ruins of a CDCA research lab in 2074. Perhaps some of the bomb fragments or CDCA experiments are still intact enough to rethread some poor schmuck's DNA. Perhaps the CDCA was experimenting with non-arcanowave mutations, and some of the mutagen serum is still around (although there are four chelonian specimens that are likely to dissuade anyone from investigating too closely). Or some idiot wired a dozen Helix Rethreaders into a feedback loop because he wanted to "see what would happen".
Perhaps the PCs find a mysterious clue about the Jammers working on an early prototype of the Chi-Bomb, but they ditched it due to "freaky side-effects, worse than the freaky stuff we're used to dealing with". Some random nutjob finds the prototype, tries to get it to work, and of course the PCs have to charge in guns blazing to stop him, but aw shucks guess who was standing too close when it "fizzled"?
Or maybe a new type of Feng Shui site pops up in 2074 with "raw" or "unstable" chi flow, and maybe defending/linking to the site allows a character to pick up a random Mutant schtick.
Another idea: Way Awful Failure when a Cyborg is using an Agony Grenade or Helix Rethreader, and one of the PCs is standing too close when it all goes pear-shaped. His DNA gets scrambled, but he can now pick up Mutant schticks.