Point 3 in particular suggests that when two pilots are flying in the same aircraft they can both log all of the hours. Only one of them can log as PIC, however. Does this mean that building total hours just became half the price if you share the controls with a buddy, or am I missing something with these new EASA regulations?
You're missing the fact that there can be no co-pilot on a plane certified only for single-pilot operations.
With the exception of a student flying with an instructor, on such a plane you're either the PIC or a passenger. On a multi-crew plane the PIC will indeed log
all of the flight hours as PIC, the SIC will also log
all of the flight hours, but only as SIC. They don't have to split them in half or keep track of who has actually acted as Pilot Flying and for how long, as they are both operating simultaneously albeit with different responsibilities, regardless of who is handling the primary controls at any given time.
Ciao,
Dg800