I think painting the side trim makes the side of the car look very messy and untidy.
The doors already have several lines and adding to them does not complement the design well. When it is grey or black or any other contrasting colour, it harmonises with the doors better.
I also think that all the grey parts should be painted the same colour ie, mixing black grilles with grey plastic side trim, etc doesn't not look good.
This is just my opinion obviously and I think you should do whatever you want with your own car, which incidentally looks great overall.