[AUgrad2006]

First off, welcome aboard! It's always good to have new officials around. Now to answer your questions...

Question 1:
The way I read it is that the clock will start on the ready for the following cirumstances (a,b,c) unless the clock was stopped for a reason under 3-4-3 or was stopped for an untimed down.

This wording might be slightly redundant as there is no situation I can think of in which there would be a snap following an untimed down except in the case of an extended period due to penalty, but the ending of a period is covered under 3-4-3g so it would appear it is just a reiteration.

Question 2:
3-4-2 a, b, and c are the situations in which the clock would start on the ready. They are the only cases I can think of when the clock would stop other than what's listed under 3-4-3.

Big Picture: Unless it's a situation listed under 3-4-3, the clock is starting on the whistle.

Hope this helps!