"How about some basic citrus physiology -- triggering of flowering, acquisition of cold-hardiness, effects of various rootstocks? Or propagation technique?"
That sounds like a great start! How about 'why baby fruits fall off'. Ferts & when not to fert. Growing in pots. And maybe open Q uestions the last 10 minutes or so.
Can't afford it but still contemplating going. Would love to see my buddies again & learn more.