1. What happens if that A/C is certified single pilot
As long as both crew members can perform their duties from their seat, then nothing. Basically, must be able to do an OPC/LPC from whatever seat you sit in.
2. If operated as Multi crew which I know that is down to the operators discression at times, do the hours in the right hand seat count if PNF.
Yes
3 Do the hours in total count towards the Multi crew hours needed for unfreezing the ATPL.
Yes. However, as said above, you will need a proper JAR25 type to be issued the actual ATPL licence.
If the A/C is on a JAR Ops AOC carrying Pax and the A/C is able to carry 9 pax as the KA200 is, buy only configured for 6 pax, Is the Operator legally required to operate 2 crew and do those 2 pilots have to be type rated.
Doesn't make a difference how many seats are
actually fitted here. If your company operates the aircraft (as per the ops manual) as a multi crew aircraft, then yes, it will need 2 crew and yes, both crew will need a type rating.
LASORS is suprisingly clear on this subject.