Input about alignments?

[SRD Art]

For those that autoX, I am interested in what you all have experienced through setting up your own cars. I've read on different forums very varying opinions about alignments. My control arm instructions have an aggressive recommendation over stock however some people say to go way beyond that. For example one opinion may be .5-1.0 deg of negative camber while other folks are running up to 2.5-3.5 degrees negative. One may say 5-6 degrees of caster is good while others preach 8-9. Some say toe in and others toe out while how much toe varies.

I have two cars I'm building, both will have complete aftermarket Pro-touring suspensions, one will be mostly street duty and some autocross while the other will be mostly autocross with some street. Tire size and weight are different between the two, one will be around 3700 lbs race weight and on 275mm 300 TW street tires while the other will be around 3400 and 315mm Rival S's.

1. Should I anticipate changing the alignment a few times before it's right?

2. I don't have the means to go out and try several different alignments on each car to see what works best, where do I even start?

3. Is an alignment really individual to the car or it's a general rule for all cars?

4. With all other factors involved, how do you tell if the alignment specifically is right or not right? Tire heat? Handling? Tire wear? ... I.e. tire heat after an autoX run is xx so therefore should the alignment be changed or the shock valving adjustment or the spring rate or the sway bar, or... ?

Thanks for your insight.