1990 Opel Corsa bosch distributor rotor

If you are concerned about it, just replace it. It's like a $5 part.

The distributor rotor is new,and if it is only cosmetic issue,i am in no hurry to replace it.
So base on the photos that i provided-will those defects might caused ignition problems?
thanks in advance.

No, unless you see deep cracks anywhere, it should be fine.

By the way,when we are talking about crack that cause ignition problems,does that mean only to the situation where the crack is penetrate through the plastic and it can be seen from the both side of the plastic(the inner side and the outer side )?
And not,also,to the situation where the plastic is only scored,is not penetrate the plastic,and can't be seen from both sides?

A crack is only a problem if it provide a path between the electrode and ground. Afain, this is probably a $3 rotor so when in doubt, replace it.

I understand that the best solution is to replace it.But,just to be sure for the next time when I will check cracks on the cap or on the replaced rotor-
if there is(for example)a crack between electrode to the ground.does The crack depth has to penetrate the width of the plastic(until you see it on the other side) in order to cause the current flow through it or it is enough that the crack will penetrate only half way into the plastic width in order to make the current flow through it?(The path of the crack is the same on both possibilities,only the depth are different)