Regards the Iris Harrier in FSX.
I have it and it works quite well , I added the  "Hover" contained in the freeware download titled  "  controls & effects for a Harrier aircraft    By Rob Barendregt  RCBhc-15.zip " .
While you can do a vertical take off in the Iris F-35B with full fuel tanks , you have to reduce the fuel load in the Harrier to achieve a vertical take off.
Its Documentation/manuals are contained in the aircraft folder of FSX.

Cheers
Karol