From: Upstate New York
1) y, set & forget. you can adjust any of the 3 PZ hexes w/o interrupting the patrol.
2) a PZ is set 'til you manually change or remove it. a TF set to a PZ will auto-rtb when it needs to refuel or reload, then it'll auto-return to its PZ circuit. but it's up to you to ensure that the home-port has the fuel & reload capability on-hand, or you might want to cancel the PZ, & set to auto-disband to take advantage of an available upgrade.
3) for a sub PZ, i usually set 2 points in-shore, 1 day each. then the 3rd point is set ~5 hexes off-shore, to maybe shake off some of the accrued DL. for an ASW TF, i'll change one of its PZ points to sit on a hex where an enemy sub has been detected.
for a PZ TF, time on-station is increased by the #/days spent at each point. for an ASW TF patrolling approaches to a port, i set its 3rd PZ point to the port, full refuel, 1-day. this keeps them fully-charged, and also seems to help keep their damage-accrual down to a negligible level.
Nice ideas here! I've always just checked them all manually every turn - never really stopped to think about ways to use the PZ features to reduce the micromanaging.