Great responses - and thanks.
The Mad Linguist, Bears are Brown, Tonymitsu, Prime32 & Mushroom Ninja: I haven't actually seen VoP in use; in the right circumstances, it can be abused, of course, but the feedback is appreciated. Would you place it as a 4 or a 5?
Snakeman 830: I have Darkstalker as a 4 on my yet-to-be-updated list. What are your thoughts?
Tonymitsu: To try to balance out the fighter and martial characters, there are few martial-oriented high FP feats (many of them are 2 FP feats); I guess that if someone is going for a Leap Attack style build, it really is a lynchpin for uber-damage, thus the higher FP cost. Freezing the Lifeblood was an iffy one; I guess that because so many of the truly powerful enemies (in my campaign at least) are often humanoid, then I felt the value was right - but, keen to know your thoughts - what would you give Leap Attack or Freezing the Lifeblood?
Mushroom Ninja: Would you advocate Persistent Spell and Divine Metamagic as both 5s?
Prime32: I would have to give a reasonably convoluted answer to this (happy to do so if anyone is interested!), but my standard is that in the FP currency, 1 FP = a +2 Skill, so "Acrobatic" is 2 skill points. We do use the Pathfinder (yeah, I know, heresy) system whereby he bonuses increase with the ' +2/+2 Skill' feats.
Akalsaris: A great question, and hard to answer; it's very difficult to get a system that has the feats (written as they are), and to place a value that works for both a Min/Maxxing style game as well as a roleplaying-emphasis game. I want to try to judge them on their merits, but I have to increase the cost of the feat if it is open for, well, abuse. Thus, while Earth Spell in and of itself is not so powerful, it has extreme potential for abuse, so the cost goes up.
I will try to get more details up shortly; a bit of typing, but many thanks for the responses so far.
C.