Psionic computers can exchange information with real computers, they just can't get real fancy. But yes, on a virtual computer an eclipsed kid could pilot a non-immersive SL avatar on regular SL.
Yes, uncontrolled psionics could affect technology, that's probably how it was discovered.
They can't give you a cooking class with real food, but they can demo it with virtual food. Eclipsed like food because they're hungry all the time (...I'm imagining it as like the first month of breastfeeding but way more so, which may not be an accessible metaphor for everyone, but I was constantly hungry in a way that made everything delicious and huge restaurant portions manageable, it was actually great) and because of this experience.