Thanks for the lengthy response. Sorry I didn't get back to you sooner. I've been busy with stuff outside Fiction Branches.
You're pretty much right in that the ideas mostly wouldn't fit in with what's going on currently. Day One has to be wrapped up first before we could do any storylines involving reverse-engineering Transformation Guns and/or creating new ones the six collaborators didn't think of previously in their homebrew RPG-like sessions. In the meantime, I've already hinted that there are about six or seven yet-to-be-named ones the collaborators DID come up with (that were made real by the infamous "wish something interesting would happen"), but they haven't been named or described yet.
(Jay and Athena saw them in Mr. Matheson's 'treasure chest', but didn't pause to identify them as they'd already had a long day and just wanted to get them to Principal Davison's collection as soon as possible).
I'm not entirely clear on the concept of the Empty Gun. So basically your idea is something that wouldn't do anything unless someone puts in special ingredients. If magical potions are the ingredients, it'd be very different from the standard Transformation Guns, which I've envisioned (and described) as resembling ray guns out of old sci-fi movies and comic books. The great wave that transformed all of Earth's firearms into some sort of Transformation Gun might very well have produced some in 'rifle' or 'cannon' form. They look like energy weapons that run on magical batteries. Whether or not these batteries actually need recharging is yet to be seen, but we DO know that using them over 100 times in three minutes without giving them a chance to cool off can cause them to overheat (and explode if someone's crazy enough to keep using it without waiting for it to cool off).
The Empty Gun/Blank Gun would be slightly different in appearance, and looking less like a sci-fi ray gun and more like a paint gun or something. At least that's my guess. In any case, I'm not sure right now which of the six collaborators would come up with it if it's one of the ones that the wish made real. Perhaps Jeffries, since he did come up with the Random Gun (not knowing it'd become real and create all sorts of chaos), or maybe it'd be created later by someone.
You've hit upon one of the biggest parts of the story as I've told it so far: The Transformation Gun 'wave' that turned all conventional firearms into Transformation Guns has revealed to the world that magic is real. As Jay Duncan has noted, even those inclined to say magic is just unexplained science and quote the Arthur C. Clarke maxim ("Any sufficiently advanced science is indistinguishable from technology") are at a loss to explain just how the Transformation Guns work without conceding that they are, in fact, magical. Even if one didn't see their classmate be protected from Transformation Gun zaps through use of an anti-magic pendant (as Jay did during the cafeteria sequence), one has to admit that there's no Earth technology capable of doing what the Transformation Guns can do.
So of course it is likely that some other magical sorts might make their move. Some people will welcome the revelation of magic. Others (such as Theodora Blakely's father Reverend Blakely) are likely to be greatly upset about it to the point that they take some drastic action. We have already seen Nadine Ferguson be paralyzed by indecision due to her being afraid of real magic thanks to her strict religious upbringing.
The idea of the Sisterhood of the Stone learning about some magic beyond that of the stone, the Transformation Guns, and the anti-magic pendants is one that occurred to me, but if it were to happen, I wasn't thinking that Linda (Jon's mother) would be the one to teach them. I was thinking more along the lines of Athena's family members or acquaintances. When I last left off, I was setting up for Linda to enter the story proper (and maybe we'd find out what she's been doing all day while most of the cast has been either getting zapped by Transformation Guns, chasing after Transformation Guns, or both), but I wasn't thinking she was anything other than another ordinary human having to deal with a greatly changed world.
Hmm. You seem to suggest that MTI might try to profit off of this by creating related projects and selling them. Well, Samantha Duncan, Ryan Leeson, and some of their colleagues might disagree, but given how unscrupulous corporate executives can be, there probably still are plenty who might overrule them and go ahead anyway. Things are likely to get confusing as people (not just at MTI but just about everywhere else) try to figure out the new status quo and how to take advantage of it.
Anyway, as soon as I have enough drive, I'd love to continue the Transformation Guns story. Not sure I'd use all of the ideas, but thanks for your thoughts anyway.