I also hate PP's...
I would just classify the cars by classes like in GT2 Arcade Mode, and make GT mode races based on that (stock cars only).
Why intentionally limit the game?
Because I think the point of being so many cars in Gran Turismo is to drive them and feel them like the real thing.
PP does not interfere with this at all.
Of course there will be a dominant (or two) car in every class, but the difference will not be that much
How can you tell?
and it's up to you the car you choose... I would also take this for online races.
You're basically limiting online to a mode where everyone is forced to use the same car to be competitive.
Per example:
Class S: Ferrari 458 Italia, Merc SLS, Vette ZR-1, Lambo Gallardo & Murcielago, Merc SLR, Audi R8 V10, Nissan GT-R...
Class A: BMW M3 E92, Maserati GranTurismo, Lexus IS-F, Audi R8 V8...
If those cars really belong in the same class, PP would ideally lump together. Depending on the options presented in GT5, there's really nothing to be concerned about. Perhaps PP resolution can be specified for online races. Ex, allow cars with 600 +/-10PP, or 800 +/-20 PP, etc. Or have a one make race, or a theme race that only allows certain untuned cars, or etc.
Of course some cars will be better than others, but it is just like reality! If you don't like that, go to tuned car's race, but I think we GTfans love the fact of "feeling like the real car"
Tuned cars are real. PP is as real as your method. It's actually more realistic than your method for a professional/organized race event.
For tuned cars, I would not mind some kind of points... But of course not "magically" adding power or weight, but buying parts in GT Auto.
The difference between Quick Tune (which isn't even PP) and GT Auto is purely illusionary. QT is basically the same code that is used in GT Auto with a smoother interface. You're kind of fooling yourself if you think GT Auto is more realistic. QT is basically like telling a mechanic how you want your car to perform and letting him figure out how to get there.
For the sake of variety, I hope to see part tuning in GT5, but tuning will be lacking if it doesn't give you the flexibility of Quick Tune.
And again, PP is getting mixed up with QT. I think it's borderline ridiculous to want to get rid of PP. It's just necessary. It should be standard in any racing game. QT is basically an interface. Some people want to feel like they are a guy who owns a car so they like to have the interface mimic a parts shop, fine. Other's just want a driving sim, also fine. But PP is not QT, and buying parts isn't really anymore realistic outside of a role playing element. This is completely true for weight as the coding between the two would essentially be the same. Power is more complicated because changing out different parts has different effects, but who knows, QT could easily be simulating changes in fuel flow, compression, etc.