I wouldnt put a split ring on John,my boys are microchipped.Rings can often get caught & some birds do pick at them
Personally 3/4 toys in the cage is sufficent, be sure to move them around or swap them with different ones, this wil help your baby to be more accepting of new toys when introduced, greys are often wary of new toys.I also had the perches lower down in the cage to start with,gradually moving them up a few inches over the firat week / 10 days.
for the first week or so i had a soft towel with newspaper on top in the bottom of the cage,this will soften any falls your baby has.
Supplements are debatable subject here some believe if your baby is getting a full & varied nutrional diet then there not neccessary,i add a vitamin supplement 2/3 times a week for mine, the same goes for a calcium supplement.