I would honestly MUCH prefer to pay with gil. GP is MUCH more annoying to come by. I'd also bet that it would be a far simpler task to add items to a standard NPC vendor than to change a part of a complicated menu-based system which hasn't been touched much in the last decade. The "HQ crystal should HQ more" thing would definitely be nice, but also probably more trouble than it's worth since they were only added/designed to allow for signing synths. I'd love it if there was a way to preserve the signature on signed cursed gear though
Please no. ~_~
It's a bad idea to spend dev time on making a sidegrade/spacesaver reforge stage when they could be making actual new gear instead. Especially since it would take 16-20, far from inexpensive, upgrade stages per slot to reach that stage, plus the most-likely astronomical costs involved if it follows the same pattern of prior reforges. (Yes, certain upgrade stages are skippable, but that's the "proper" progression.) ...Wouldn't mind too much if they were added as Synergy recipes during an otherwise already slow month at some point though. XD
It's also a bad idea to make any reforges master-only since that does nothing but lock out anyone who isn't already "done" with the job before being able to benefit from it.