
Methods: I looked first for presence and absence of classes for each faction, then normalized so that the most prolific faction's value was 1, thus all numbers are a ratio of the top faction in that category.
Weighting function: I looked for races/classes that were significantly constrained by addition of faction restrictions and only counted them as half. Ironically, this only affected the SL numbers, so call bias if you wish.
For an example of racial constraint: earth gens in SL cannot be monks, whereas every other faction that allows monks, and allows earth gens, the combination is allowed. The racial constraint category only cropped up for SL and most of the human subraces, I found no restrictions on bard or barbarian similar to the above. This was surprising to me.
The only significant class constriant I found was SL harper (only drow as they must be nonevil).
The numbers:
Weighted race
1.00 MA
0.96 NC & TC
0.91 SL (1.00 if you unweight the equation)
0.79 AO
0.29 RK
Weighted class
1.00 RK
0.88 AO
0.84 SL (.88 if you unweight the equation)
0.81 MA & TC
0.75 NC
Conclusions: If you put any stock in my weighting function then everything seems well and good to me, high on one list usually implies low on the other, though I feel for the guys in RK when it comes to race choice, NC might also feel a little shafted.
If you hate my weighting function, SL is overly lax on the restrictions, Praise Lolth!.
Props to the devs either way

Personal Findings: SL feels so constrained to me because i love monks (bye bye human subraces) and full bab casting classes (pally & ranger), not that we are overly restricted in choices.
Disclaimer 1: Quick and dirty implies a few minor errors may be present
Discalimer 2: I realize not all classes/races are equal, harpers are almost nonexistent (for good reason) whereas pally 5 is an awesome bargain, RK only has one ecl 3 race to pick from etc, but that is not considered in this analysis.
Disclaimer 3: Give RK earth gens, it's the only thing dirtier than a dorf.