OK, but..

For a real transmission(manual, auto or CVT), 起步的瞬间离合器打滑是不可避免的. Howerer it is not 'ideal'.

(1) To avoid slippery, the best CVT has to have a infinite low ratio. That is 'ideal' transmission I am talking about. The locomotive example is very close to it.

(2) A slippery clutch cannot transmit 100% of the power. It is not 'ideal'.

(3)-(7) Just remember
a. 功率 = 转速x扭矩 = 力x速度
b. 变速箱变的是扭矩。
I have no objections if you don't violate these rules.

We are talking under different assumptions. I am talking about 'ideal' transmission that can possibly have nearly infinite gear ratio, while you emphasize on real world slippery case that is way far from 'ideal'.