FlexibleResponse,
There is no requirement under JAR-OPS or JAR-145 for a licensed engineer to inspect an aircraft before each and every flight.
There is a requirement for the aircraft to be inspected prior to each flight (a pre-departure inspection) but this can be done by a suitably trained and appropriately authorised pilot.
Under some approved systems of maintenance there is a "daily" or "72 hour" inspection which must be conducted by a licensed engineer.
I don't propose to list airlines here. I did attempt to send you an email, but your profile says you don't wish to receive them. Your choice I guess.
In the European airlines I am familiar with it would be unusual for an aircraft to fly more than two or three sectors without having a pre-departure inspection done by a licensed engineer.
Usually, when an aircraft passes through a company maintenance base the pre-departure inspection will be carried out by a licensed engineer. When away from a maintenance base the pre-departure inspection will be carried out by an appropriately trained and authorised pilot.
Sometimes a pilot will conduct the pre-departure inspection even at a company maintenance base if all the licensed engineers are otherwise engaged - eg on AOG work.
I am not aware of any safety issues arising from having suitably trained and appropriately authorised pilots conducting pre-departure inspections.