I agree that using "hooked" or "addicted" would give the sentence essentially the same meaning in the sample sentence about skating.It would be "she is addicted to skating" -and there's not really a difference.
Yes, that's also true.I'd even say that "hooked on" is not only less formal but also slang, no?
1. Bent or angled like a hook.
2. Having a hook.
3. Made by hooking yarn: a hooked rug.
a. Captivated by or devoted to a custom or thing: She's really hooked on gardening.
b. Addicted to a narcotic.