Yep, I think you hit the head right on the nail with your
learning method. URC does a very good job of staying
on top of the latest IR codes (EXCEPT WHEN HANK EISENGRIN
LETS HIS GUYS GET BEHIND WITH CODES FOR OUR PRIZED VIZIO
AND POLAROID DISPLAYS!) Just kidding.

Your macro looks good provided there is enough space between
the steps. Again, if there is an RF base station available
for your your remote - which has IR outputs, one of which
talks directly to the TV - I would highly recommend using
it, if nothing else, so that dreaded "point and prey"
type of macro works as reliably as possible.