Just a few things i would like to add here to be considered , ........
1. I think the qualy, needs to be fine tuned as to what day is preferable to most people given the fact that everybody has different circumstance.
2. Absolutely.... YES.... that I think that all GT3 cars should be used. none should be excluded, reason for the yes answer is that the cars will be comparatively the same as in performance, heavier cars will have more get up and go on the straights and the lighter cars will be more agile on the bends and corners, but overall across the board the cars will be compeatable with each other.
3. And the endurance races should be a different entity all together, although I would still like to see these races under our GT3 World Tier Championship Series ....GT3 WTCS, But could be named GT3 World Tier Championship Endurance Series GT3 WTCES Or Just have it like what arkitekt888 said.