Congrats on the addition!
Morelia are amazing. I love every species from that Genus. As a matter of fact, I love all the herps of OZ. Haha. I have a pair of JCP's from Headhunter reptiles. Id say feed your hatching every 4-5 days. Keep them on rats! Switching from mice to rats is nearly impossible and feeding 8 mice per feeding gets really old really fast. Haha.
As far as handling I would give him 5-7 days to settle in, then feed, then handle 2 or 3 days later. The handling should be pretty short. Hatchlings can be pretty nippy, but I havent had that problem at all. Your setup sounds good, but they will outgrow that tank quick. JCP's love to roam at night, so I have my hatchlings in their adult enclosure, a 4x2.