#1 Is this compatabke with the F and P dryer WH8560P2 for stacking with a stacker kit?
Yes they will suit each other you may also look at the optional extra stacking kit from F&P model No: 428122 Once you add these together you may also want a handycrew person to deliver and stack all three items together which there is a small fee for this service
#2 Can you tell me the actual diameter of the porthole door opening please so I can compare it to my 10kg existing machine
The door cavity is 350mm wide.
#3 Does this machine have autofill for the detergents?
No, currently the only model that features auto-dosing for detergent is this model: WH1260F1 by Fisher & Paykel. Other brands including Bosch and Siemens have Auto Dosing (dispensing) models too.