To answer one of your questions, no the house probably doesn't need to inform leagues of changes to the shot unless it's pretty drastic. If it's still a house shot, it's still a house shot. The house probably makes a lot of tweaks to the shot over the course of a season to keep it playing about the same. I know my house will add/subtract a foot from the pattern, or add or subtract a little head oil to keep the hold area and backends playing about the same as the weather changes, and I wouldn't expect that my league be notified.
That being said, if the shot is significantly more difficult, maybe an advance notice is in order.