Sorry, I didn't see your post before... It's true, it's not immediately obvious the way I wrote it, I had to think a bit to remember what I wanted to say. So:
VP = BaseHitPoints * (PlayerLevel * vpmult(autobalance.2da) - 1)(only if mult > 0) + HitDie(classes.2da)/Levelup + CON * Level
Here you have several references to levels:
1. PlayerLevel: "All values depend on the player level, which is determined from experience. This means that if you have enough experience for level 33, the game will consider that level even if you haven't levelled up yet."
2. Level: "Level = Level(Class I) + Level(Class II) + (PlayerLevel * levelmult(autobalance.2da) - 1) (only if mult > 0)"
3. Levelup: "At levelup, you gain: 6-12 points depending on your class"
So, the base is BaseHitPoints (which is multiplied by (PlayerLevel * vpmult(autobalance.2da) - 1) if the vpmult is > 0). To that value, you add some amount for every level up (ie. it's not retroactive, if you get a character at lvl 6, they will not get the bonus for the levels up to 6, they will only get it added once you level them up [I haven't checked this recently, but I think that's what is meant, and if I wrote it down I must have checked it back then]), the exact amount that's added depends on the HitDie column in classes.2da. Then at the end, you add the CON modifier * Level (as it is defined above).
Force points work the same way, the only difference is that there is no autobalance scaling of the base value (there is scaling of the attribute modifier however, because of Level).
As for the LEVELUP for Skill, that's the points you assign to skills when you level up your characters. As you probably know, the amount of points you can assign depends on your class as well as your INT modifier. Again, only player controlled characters get this part, since non-playable characters don't level up.
[I just realized, I haven't checked or at least don't remember having checked what happens if you change the PC to another party member. Is the PC's level still used as PlayerLevel for autobalance (which is more likely I think) or is it the party member's? But if it's the PC's, then the party members that you get at higher levels have quite a disadvantage against the enemies compared to the PC and the party members you get at lower levels.]
Hope this helped clear things up!