Awesome spider but i dont know much about them sorry. Tarantulas go darker before they molt could be the same for them?
Probably about to molt then and yeah grow up essentially
No they will eat prey on each other.
I don't believe they molt once they're mature. They do growing up though.
It def looks like a Phidippus Audax subadult. I have one as well 3rd or 4th instar looks the same just slightly different markings. I think Audax do 8 molts before they are mature but I could be wrong.
When I first got him he wouldn't eat fruit flies or moths for 3 days the 6th day I gave him a cricket and he munched on up, 2-3 days later I gave him another and he ate 1 leg then the rest, will he hurt himself
I would say that if the spider is willing to pursue it and visually you don't think it's going to be so big it's going to hurt it, it should be okay for the jumper. The spider will avoid it if it thinks it's too big. With a lot of my spiders, I tend to feed larger prey and then I can feed them less often. Jumping spiders are pretty tough little guys. They can take down some pretty big prey. If you're on the edge and you think it's okay but not positive, you can always remove one of the cricket's back legs. Just gently tug on the leg and it should release on its own.
They dont really overeat in my experience. They will eat and hunt actively until they get that fat chubby look. Then in my experience either ignore prey or stalk less fervently sometimes just watching it. Sub adults hide when they dont need food and stop eating around and during molting time. If it looks chubby and is lazy about food that usually means its full. Wait 2 or 3 days and feed again.