Most of my snakes have lived long lives too...like all living creatures, it's a matter of good genes, good care & good luck. I read somewhere that the oldest snake on record (at the time) was a ball python that lived to the age of 47 years in a zoo (I don't recall which zoo), so yours might even exceed 30 years, who knows?
The only thing I would suggest is to feed smaller & less often: the slightly-diminished appetite you're seeing is quite normal. While snakes continue to grow their whole life, that growth also slows down the older they get...you can verify that yourself, by keeping track of how often he sheds. Your ball python looks very healthy & likely has many more years ahead. The feeding schedule he's on seems more frequent than what I'd do, and if you gradually lengthen the time between meals (& downsize the rodents a bit) you may find it better matches his needs. (I feed most adult snakes about every 2 weeks, and some more like 3 weeks, depending on individual needs. BTW, I keep various kinds of snakes, no ball pythons at this time, but I've had them in the past.)
About shedding: I'd recommend not feeding an older* snake (*especially, or one with any health issues) when you can tell they're nearing a shed cycle. They don't "multi-task" as well...both shedding and digestion requires extra water from their body to complete the process, and you may find that a snake has trouble shedding (gets stuck in, or sheds in a zillion pieces) if they've tried to digest at the same time...because both processes cause them to be dehydrated.
Reply With Quote