I'm building a detached garage with 2nd story living space that is
about 14 feet from the house. The two are connected by the deck that
also wraps around the house. Basically you go between the house and
garage via the deck. I powered the garage via a 100amp breaker on the
main box to a subpanel in the garage.

But I've also installed an outdoor light fixture on the door of the
garage that opens on to the deck. And I extended the 3-way switches
out to a box just inside the door. I did this by running two pieces
of uf, 14/3 and 14/2 out to the garage inside the deck joists.

So I have a lighting circuit from the house system extended into the
garage and not sharing any of the wiring connections in the garage off
it's subpanel. Is this ok code wise? If not is there a way to make
it ok?