Try referring to the UK CAA publication CAP 804, which you can download here;
CAP 804: Flight Crew Licensing | Publications | About the CAA
This is not an EASA publication, but UK official guidance on EASA licensing.
Refer to:
Section 1 General Information, for definitions;
Section 4, EASA FCL 035 for crediting of flight time.
These should answer your questions.
In brief, flight time is only countable if in a powered aeroplane for the purposes of an ATPL. No time in synthetic training devices, whether full flight simulator or lesser machines, is countable. NB: see post 4 below for a correction to this.
Good luck!