Why is it so important that he's carrying better now?
I have a 12 and 9 year old that I admittedly get a little excited when they do well, but I'm trying to control how much I push them forward. I feel your anxiousnous.
I've had discussions with several respected coaches that share my feelings that kids this age should be focused on technique even at the expense of scoring better. Every proud parent wants their child to be the next prodigy, but you'll be better off in the long run to teach fundamentals now. Fundamentals are much easier to learn with a simple conventional grip and a ball that is easy to handle.
Being good at 8 means he'll beat some 10-12 year olds. So what? Teach him great skills now so that when he's 12, he's giving you a run for your money.
Also, wait on fingertip a few more years. Everyone is different, but too often kids struggle if moved up too soon.