Mine was Gas Version, so I don't have first hand experience with D4d . Other D4d owner can best give you answer.
On synthetic versus mineral, I did also mineral to synthetic and back to mineral for up to 35K PMS but since I'm using LPG fuel now I switched back to fully synthetic for extra engine heat protection. Bottom line is when you do high performance driving or modified engine setup then go fully synthetic for extra protection, if you are just using your car as daily car without passengers and no extra high revs then mineral oil will suffice
Toyota gave us stock engine filled with mineral oil, so it means mineral oil is best for our engines, not unless you do modification like mine
Shell oil? Casa don't allow other oil and oil filter besides their own.