Pressure
Sometimes parents new to unschooling don't realize that their lack of deschooling is creating pressure on their children to "perform" in one way or another. Deschooling should involve nothing schoolish for children for several months, and nothing schoolish for the parents for at least a year (depending how many months the person was in school, or university, or teaching in or working at a school). More in deschooling is here: Deschooling.

In April, 2014, Meredith Novak wrote (to a mom concerned that her son was a slacker):

Lots of kids go to scouts and don't trouble much about badges and whatnot. Lost of kids join sports teams, or pick up instruments, but aren't all that interested in practicing. There's something wonderful about being on a team, in a club, that doesn't necessarily translate into "doing work". And "doing work" itself doesn't necessarily translate into more skills. Some people are naturals. I have a co-worker who's been doing my job five years longer than I and I'm better than he is—so much better he asks me for help. I don't work at it, don't go home and practice, it's just a natural difference in aptitude. I guarantee you there are kids on your son's team who do as little work as he does and are star players. There are kids in scouts who get badges as easy as pie, never really working at anything, because it's all fun for them.

I am looking for input on how he should fulfill these obligations within an unschooling framework.
What happens if he Doesn't meet a certain standard? Is he kicked out? If so, then that's worth evaluating Before spending money—maybe it would be better to find a cheaper or free club instead, at least for a year or two until you've all had plenty of time to deschool. Are people actually relying on him? If he's not a natural and not improving much, then chances are everyone on the team knows that—that's Why he's on the bench. If he's friendly and personable and has friends in the group, that can be enough to remain a team member even if he doesn't often play outside of practice. Teams can have not-so-good members they keep around because what they bring to the team can't be measured in goals or badges.

If he won't be kicked out and isn't ruining the team's chances by his presence, then there Is no obligation. A lot of clubs for kids have "work" that's really more about reassuring parents that something "worthwhile" is going on—look mom and dad, it's not just a social club... when really, to the kids, it Is a social club, a chance to get together with people who share similar interests and pal around for awhile.

I am looking for input on how he should fulfill these obligations within an unschooling framework.
It doesn't matter what framework you use—unschooling isn't a magic formula, it's based in human nature. And human beings often resent having other people tell them they are obligated. It can make people pissy, recalcitrant, and passive aggressive. That's as true of children as it is of adults. When you pressure kids to "meet obligations" they don't learn anything good.

Even if you successfully pressure him into practicing and doing little tasks to get badges it won't make his life or yours any better. It won't make him happier set him up to care about those tasks. It's more likely to set him up to look for the absolute least he can get away with—just like school. It's one of the very common human responses to outside pressure. In fact, every time you put pressure on him to practice, you're setting all his deschooling back to square one, undermining any growth toward self motivation.

Unschooling involves recognizing that fighting against human nature doesn't make better people.

original might still be here

Sandra Dodd, years ago:
With anything, if a family moves from rules (about food, freedoms, clocks, what to wear) to something new there's going to be the backlash, and thinking of catapults (or trebuchets, more technically, or of a rubber band airplane, or other crank-it-up projectile vs ...) the more pressure that's built up, the further that kid is going to launch if you let it go all at once. —Sandra Dodd
Gradual Change "Finish what you start" is a bad policy Control, and its related problems