I must admit , I don’t fully understand your question(s)
all i can say – as i understand it:

…the opportunity after the order to give a rating from…

i would think some rating plugin would do what you want to do

The Order field where to change the customer data to adjust.

sorry , I don’t understand what you want to adjust where

On my side sees the shopping cart plugin quite clear from looking a ne solution?

sorry , I have no idea what you are saying here