The set up of a guitar is a combination of factors, all of which can be adjusted to make the instrument easier to play. String gauge and fitting is crucial, as is the height of the bridge and the tension of the truss rod (which passes through the neck).
I set up guitars for the individual as to some extent the adjustment is a matter of taste. Some people like heavier strings and a higher string height (action) and others the opposite.
The right set up can transform an instrument.
I also undertake electrical and body repairs to guitars. Frequent problems with electric instruments involve short circuiting of the wiring at the jack socket. This can be easily and cheaply repaired. Pickup, bridge and neck nut replacement can also be done.