if all the weights are the same, and we take RPM out of the equation.....

car #1 isn't even in the running.
car #2 is quickly dismissed because that sounds like something that will only do well at very specific tracks....if anywhere
car #3 is only slightly favorable to car #2. but everytime i ask myself "why?" i end up with an answer that is directly related to RPM.
car #4 is the obvious choice to me. it's the only one that you KNOW will have a solid powerplant for racing.

to me there is no consistent way that torque "matters." climbing up the hill at Road America it matters a lot. but a fast, flowing track with high speed corners it matters very little. i think it matters less in lighter cars than it does in heavy cars (which kind of answers the third question). the more rubber you can put to the pavement via advantage in drive-wheel suspension layout, wheel size, and drive layout, the bigger of an advantage it is.

i don't think there is a consistent, repeatable way to treat ALL cars in the ITCS equally for torque. peak HP can be used because it's always measured within the usable RPM range. this is not true for torque. i don't know if i think it should be 100% ignored, as some cars are so far "out there" one way or another that they warrant some sort of consideration, but the means in which that is done doesn't seem to be the goal here.