Improved Optics -- I'm kind of reluctant to do a significant range booster as it opens a bit of a can of worms in terms of allowing the player to off-screen enemies and such. Misery's thoughts on this one would be good.
Pizoelectric -- Maybe better as a module?
Long Haul -- Hmmm. Not sure about this one.
Scoundrel -- I think that maybe the miniboss drops -- or lack of drops -- just need looking at some time, maybe they should drop stuff.
Regenerating Battery -- Super tricky to get this right without Misery quite rightly going "Noooooooooooooooooooooooooooooo!"
Boom Fire Blowy Up Thing -- Worth looking into maybe, but probably a longshot.
Phasing Missiles -- Pretty good idea yeah. Maybe would work as a new mech missile weapon. Ghost mech anyone?
Secret Pass -- Some kind of pool replacement item might work, aye.
Regarding my initial implementation attempts. So far CouponCutter, HealthRegen, EvasionBooster, X4MissileDamage, SkeletonKey (also removes keycards from seeding), PhotoElectric, CritDamageBoost, and LorentzFactor (less the shrinking effect) have been implemented without too many problems.
More resource drops -- couldn't work out how to do this in a non-hacky manner.
Chance to not use ammo -- couldn't work this out either.
Demolitionist -- also surprisingly couldn't get this to work.
Recycling -- Looking at it, this kind of seems like a different way to do More Resource Drops, so I left this one.
So: CouponCutter, HealthRegen, EvasionBooster, X4MissileDamage, SkeletonKey, PhotoElectric, and LorentzFactor seem ready. CritDamage is also there, but there was some objection to this one, so I'm not counting it. Add in the Bloody Avenger Weapon, and that makes 8 new items so far. The existing roster of sacrifice items totals 10 (I think!) so if we go with these new ones, we're up to 18 in total. We need at least another 3 to fill every pedestal for a 7 floor run.