Hi.
There are no problems as to the height of the shots, only common sense; today they are used to 40/45 cm of the floor, 20 years ago they were used to 25 cm. In the placement of cablecanal sends the aesthetics, and security is given by the capacity of the electric, so it does not matter if you place it diagonally or in a circle, the problem does not happen there as far as the confidence in that system.
Put it as you want is correct, remember to use boxes of good capacity where you make splices, and the cablecanal Schneider (type 301) is very good and good capacity.
A good system is to stick the cablecanal with its adhesive and then screw every 45 cm.
If it is sold in a streamlined market (IRAM seal) it is supposed to be regulatory, but I do not know the approval certificates that these cablecanal have.
I repeat once again, regulations are made for those who are always on the verge of evading them, you can evaluate how sure you do your job, that is in your hands.
regards