Recharging charged items...

[Spatzimaus]

So essentially you get a wand with a spell you don't know, and use an empty spell slot to power the wand, instead of the wand's charges. Neat idea.

Yep, at a cost of one spell level. One other thing I forgot to mention: I don't know about the others, but Master Dorje counts as a metapsionic (metamagic) Feat, since it's changing the slot level for a spell without changing the spell's actual level.
On the plus side, this means it counts towards prerequisites for certain Prestige Classes. Since Psions don't have increased casting time when using metamagic this isn't a problem for them, but for Sorcerers this sort of thing can hurt. I had a Psion who specialized in magic item creation (custom PrC), and he had twenty or thirty nearly-depleted dorjes in his workshop, for when he was creating items needing spells he didn't have.