I wonder if the bank of questions are geared toward a McCullough J-2 or the Air & Space 18.
Definitely
NOT for the questions cited in this thread so far. Addressing them in the order they came up,
1. I've never even seen a pitch oscillation in either model; PIO is not an issue.
2. There is no such thing as "flap" for the J-2 or 18A. They are each pre-spun to more than 120% of flight rpm while sitting still, before any take-off roll is even begun, and they lose rpm (not gain it) during the roll. There is no rotor management to be done when flying these aircraft.
3. Collective pitch is not varied during flight (except for a small rpm-trimming adjustment available on some 18As with an STC), so one won't be "adjusting a pitch angle" for steering.
4. Both are swash-plate controlled systems, not head-tilting, and you're not going to create problems with stick position during taxi. I often taxi the 18A without touching the stick at all; it doesn't really matter where it is. Abrupt stick movements on the ground are simply not a concern. For the 18A in particular, you can apply the rotor brake for taxi, and that puts it into flat collective pitch, so the rotor won't be doing anything at all.
These questions appear to me to aimed at Bensen-style fixed collective teetering rotor systems for which rotor management is a big deal, but the questions are just very badly written.