If I sent to normal mechanic for normal services be it minor or major - would it be a problem or not?

No definitely not. As the unit will not get in the way of you major or minor service. However if your car warranty is still on its course, I advise you that the warranty is still a grey area. I do have customers who install this system even though their car warranty is still valid, even though I told them about the warranty claims. Should not be a problem but its just for precautions.