Oil change questions

Well, it was time to change the oil in the old bug smasher. Seeing this
is my first time, I hired a mechanic to walk me through it. Of course
it is pretty straight forward, but a few questions came up.

1) The oil filter specified a torque setting of 16 to 18 ft-lbs. The
mechanic told me mot to do that, just 1 more turn after the gasket
seats. He said that if I used the torque setting, it would be very hard
to get the filter off again.

What do you all do? Torque to the specification, or just 1 turn?

2) A lot of people to change the oil every 3 months regardless of hours
on the oil. Combustion waste gets absorbed by the oil. The mechanic
said he liked that idea because it would generate more revenue for him,
but he felt it was not really necessary.

What is your opinion?

TIA!!!!