@lahatta: In the first picture that piece is very small and they should have been able to fabricate it so the gap was very minimal (even if the wall is not square).
The second picture if the overhang is not consistent then there is a problem. More than likely the templater did a poor job or the cutter did a poor job. Installer just puts the granite in and has little to no choice if the pieces were cut incorrectly.
How was the template done? Measuring tape? Cardboard pieces? or computer aided?
I think the inconsistent overhang is a place where you have a lot to complain about.
I am sorry but seems like you will have to pressure them to fix this, they will be very reluctant to fix these issues.
Good luck!
Q