Yep, that's right, log PF time in the PIC column
NO That's complete Tosh! RTN11 you should be ashamed.
Part-FCL (Page 9) Definitions:
Pilot-in-command’ (PIC) means the pilot designated as being in command and charged with the safe conduct of the flight.
‘Pilot-in-command under supervision’ (PICUS) means a co-pilot performing, under the supervision of the pilot-in- command, the duties and functions of a pilot-in-command.
Nowhere is it stated, or even suggested, that being the Pilot Flying equates in any way to being PIC.
EG:
PF sets up a Heading of 330
PM monitors that PF set 330 and that aircraft responds correctly
Either is irrelevant as to who is PIC
PIC = The person who made the actual decision that the aircraft should fly
a heading of 330.
The OP may only be a very junior 2nd Officer still learning how to be a co-pilot. It is only senior co-pilots, who are learning to be Captains, who will be allowed to "perform, under the supervision of the pilot-in- command, the duties and functions of a pilot-in-command" and then (presumably) the whole flight will be logged as PICUS, provided the actual PIC did not need to override any decisions, agrees and endorses the co-pilot's Log Book to that effect.
I foresee another long thread on this topic.