So way back when I started posting this random alternate rules posts, I made the ruling that Monks were psionic characters, which is a fairly obvious and sensible ruling. Monks have always been linked to the more fully psionic classes, and there are even a few Monk/Psion hybrid type prestige classes as well, the same way there are Fighter/Wizard style ones.
So working with this understanding that Monks are psionic characters, does that mean ki points are power points?
It makes a certain amount of sense and would further create synergy between existing psionic classes and the Monk. The questions is whether or not it is overpowered. I mean, Monks typically have 10 or so ki points, plus a few from a high Wisdom. That is assuming a 20th level Monk with no vows or anything for bonus ki points. A 20th level Psychic Warrior has a base of 128 power points, plus additional ones based on his Wisdom. A Wisdom of 16 will net a Psychic Warrior another 30 power points. Now, granted, most Monks can't do much more than penetrate damage reduction and do a few supernatural abilities like dimension door or heal themselves, so having 100 more ki points than normal isn't exactly game breaking in nature. A Qinggong Monk could more easily take advantage of power points and ki points being interchangeable, but that depends on which ki abilities he selects as he grows in level.
I don't know that this is necessarily game breaking, but a Monk with a few dozen power points to use as ki points could pretty much have an extra flurry attack every single round of combat ever. The only restraint might be that those power points would be more useful with psionic powers like biofeedback or offensive or defensive precognition, rather than just spamming on extra flurry attacks.
I dunno, ki points being power points does make a certain amount of sense, they're both internal power sources based on mental attributes used to do supernatural stuff. I don't think I'd automatically make them interchangeable. Perhaps a trait or feat to do so? They are similar types of energy, but the ki points are very specialized in their purpose, the Monk uses them to enhance his own abilities and in a few occasions do spell type stuff. Perhaps make it a feat that allows a one way transfer of use, power points can be used as ki points. My campaign only has one psionic character and no Monks, so it isn't like anyone is clamoring for this sort of adjustment to the game.
I dunno. Whatever.