I did some tests to find out the effect of certain skills on your character and I thought, I'd share my findings:
The hit points of a character are given by 7+[(4+L)*E/2], where L is the level of the character, E his endurance, and [x] denotes the largest integer less or equal x, i.e. rounding down. Only base and bought skill levels do affect the hit points.
The carry capacity of a character is given by max{50+40*S, 450}, where S is the strength of the character, including all external boni (items, divinely touched,..). The trait "Strong Back" increases the carry capacity by a factor of 4/3 so the maximum cc of a character with that trait is 600 (which makes strong back one of the best traits, imho)
To deduce the percentage that quick strike grants +2 AP, I went into combat mode and counted the number of turns the character got 6 AP over 100 turns.
Quick Strike level / number of turns with 6 AP
1 / 1
2 / 8
3 / 6
10 / 23
40 / 81
50 / 100 (and the ratio stayed at 100% many many turns more)
All the data nicely supports my claim that each level of quick strike gives a chance of 2% to get +2 AP.
I tried the same for magical efficiency. I casted Divine Host (normal casting cost 30) a number of times and noted the effective casting cost.
effective cost / number of occurences
ME 1
----
30 / 13
29 / 15
28 / 5
27 / 1
26 / 1
ME 2
----
30 / 4
29 / 10
28 / 9
27 / 7
26 / 2
25 / 2
24 / 1
ME 4
----
30 / 1
29 / 1
28 / 9
27 / 10
26 / 5
25 / 6
24 / 3
23 /2
ME 10
-----
30 / 0
29 / 0
28 / 0
27 / 2
26 / 4
25 / 2
24 / 3
23 / 5
22 / 7
21 / 6
20 / 8
19 / 1
18 / 1
17 / 1
While there is a definite trend in the data, I was unable to extract the formula due to the bad statistic (some kind of binomial distribution looks promising).
If you think that it would be interesting to know the formula (unless it is already known in which case I apologize for having bothered you with lots of numbers), it would be very nice if you could do some tests yourself and post the results to improve the statistic.
The Mad Scientist