There's no real 'requirements.' It's more suggestions than anything. To be able to run past lvl 80 mages and rangers. I personally recommend level 75+ rc before you start training at ZMI though.
Lunars are nice for teleporting to Ourania then back to Moonclan, get some decent magic exp while you're runecrafting. Higher defence/Mage level is good, Agility clothing (85/90) is great.
