I've been involved with raising many kids from birth, many of them are now adults, so I've got some opinions.
I think a 17 yo should control his finances, not the parent, who shouldn't be using most of them for thier own benefit, thinking they deserve a return, as if he's an IP
I think all kids should have full control of thier finances, from as soon as possible, say approx 5 years old. Parents should be honest and informative with money, and grant children the freedom to make thier own mistakes with money, which they will learn from. I really liked how Dazz mentioned introducing his kids to shares, which would be an excellent learning experience for children. I wouldn't be surprised if his kids become totally awesome entrepreneurs
A 17 yo sholdn't have to hold party behind the parent's back, the sort of party that can easily lead to people ending up in emergency rooms. I don't think the correct response to that is not to treat him like a total criminal either, which will only lead to more problems
I think all kids should be free to have regular parties with thier friends, from as soon as possible, say approx 2 months old (parent groups). Parents should be honest and informative about playing with other kids, and grant children the freedom to make thier own mistakes when playing with other kids, which they will learn from.
By the time a child is ~16yo, they should be allowed a few get togethers per year, on school breaks. They should be allowed to have alcohol if they choose, and have the freedom to get drunk if they choose, and be free to make mistakes if they choose. They might end up damaging the walls, windows, garden, etc of the house, which is not a reason to put a halt to the party - they will have to pay and repair for the house to look like new, which teaches them both responsibility and renovation skills.