And that modified quote you just made works fine for the senarios I made at the bottom of page 2.
Don't confuse "power points" with "levels of a power". Some powers cost less than one power point per level - such as 0.5 or 0.25 per level. Improved Body, for example, costs 0.5 power point per level of that power. So, Improved Body level 2 costs 1 power point. Improved Body level 4 costs 2 full power points.
If an adept has Magic 3 with no foci or power points purchased from karma, he can't have Improved Body level 4 because that power is one level above his limit of 3. The adept could have Improved Body level 3 at a cost of 1.5 power points. The same adept can also have 1.5 power points worth of other powers as long as their rating is not over 3 as well.
If that adept has Improved Body level 3, Improved Strength 2 and Improved Quickness 1, he used up all 3 of his available power points he got from his Magic 3. If he then spends 20 karma to get another power point to spend on powers, his level limit will now be 4 (magic 3 + 1 from karma). He can spend 0.5 of that power point he just got to get Improved Body level 4, leaving him 0.5 power points left over to upgrade other powers, or even get a new one.
The number of powers does not matter. The level of any power can't be more than your limit (magic + power points from karma).
I'm not going to get into the Foci right now.
I'm sorry if I'm not understanding your point.
[Edit - corrected math on the power points and added some more]