Thank you all, some very nice suggestions (but keep 'em coming anyway, one can hardly ever get enough of inspiration).
I'll be sure to write back here once I write things down.
yes, it is simply another version of Elementalist, but which 4 Forms to include...Animal and Herbam are no brainers, but the other two have several good pros and cons. Auram is one I like, because the weather is IMHO an important part of Nature. The sunlight is not controlled by controlling the light itself, rather than making sure there are no clouds. Terram or Aquam...Nature is not truly metals and gems, but earth and stone, again this it not living. Aquam covers the lakes and streams of nature, but not anything else, like the poisons and all other unnatural , produced or refined liquids. I might go for just An, Au and He - and then jazz it up to 2 exp instead of just 1.
Special Durations etc
I also like the idea of making some new Durations, like some of the special R/D/T for Faerie magic. Something tied to natural occurences, the life of trees and animals, migration of birds, hibernation of a bear, untill the hottest or coldest day...something like that. It needs some serious work though.
Versions of Verditius Mysteries
I'll make sure I look into Verditius again, so see if I can bodge a Nature Myster based on some of this. At this time, I can't recall that specific Verditius Mysteri mentioned.
There were also some good ideas for Flaws, to use as ordeals for initiation into various Mysteries, sacrificing some city-skills or very academic stuff. I might add some minor mystery to initiate Cyclic Magic (Positive), it seems very appropriate for Nature Magi, perhaps with some additio to the regular version.
I just had an idea, to a Nature Mystery, where the magus gains the abiloity to use Natural rather than Astrological resonance for use in Ceremonial casting, using Nature Lore rather than Artes Liberales/Philosophiae.