a 90 degree edge can theotetically shave hair. shaving hair is a test of sharpness, not really cutting ability. the way a scandi is set up, it is designed to function like a woodworkers plane. one side of the edge laying approximatly flat against what is being cut gives the plane effect. scandis are set up so that when the back edge is resting against the material being cut, the blade against the material will make an acute angle, giving the knife versatility and the ability to be very precise while cutting. a more obtuse angle, while it will still shave hair, forces you to hold the knife at a greater angle, relative to what is being cut. so, you are limited in the amount of precision you can obtain.
regarding the thickness, a thinner blade dosent need to displace as much wood (or what ever you are cutting) to get through. a thick blade on the other hand, has to displace alot more material.
as far as a choil, cutting techniques vary from job to job. i think (but am not really sure) that busses are intended for tactical use. for that, the choil comes in handy ( i would assume) . in bushcraft, the cutting style is alot different. watch some of this guys videos
http://www.youtube.com/profile?user=hobbexp&view=videos . he uses a cutting style that is nearly the same as mine, and he uses knife that are similar to mine. i am not sure, but i dont think that a tactical knife can cut quite as good as bushcrafters can in this application.
really, just go spend the 10 buck on on a mora and you will notice the differnce.
i am not trying to be argumentative or badmouth busse at all, just for this application, i dont see that type of knife as being very effective.