It is best if answer your last question first.
And the answer is 'Yes', of all the things listed by you, it is only a change in quantities under option B clause 60.4 or 60.5 which may cause a compensation event due to change in quantities.
I am not familiar with NRM2, so all I can say is that a change in People costs MAY cause a change in how a compensation event is assessed in terms of the rates that people are charged at. Having said this, under the priced based options A and B, if the Contractor references an input cost at tender as a Defined Cost, then this is the rate used for CEs thereafter. Not knowing NRM2 or how this was referenced I cannot say for certain though.
For your points 2 and 3, these are essentially Contractor risks, so will not affect how much you pay.