if we can learn other schools,
Sure can do - but it will get a handicap in comparison to our "main"-skill, wich will grow if we were to dabble in even more disciplines. But to an effect, untill we have "established" ourself, it will be more of a moot point than a possibility.
Will demons summoned with Demonologe stay in the world after they expire?
It is not all that easy to bind an extraplanar entity to "this" plane, but quite doable somewhat later on. Those planebound demons would leave their physical form in this world, but as we spent the mana to summon them, and enable them to "build" that form, it obviously takes more energy to summon something, than you would ever gain from eating it. Same applies to eating any spells or growing mystic plants as a druid. (Well, the plant could be grown, but it would yet have to absorb mana from its surroundings, wich is a
very slow process.)
We are a solid, tangible object. We can modify ourself. With practice, we could become a full-sized dragon even with our stunted growth, or modify our digestive tract to process anything we can get our jaws around.
While what you say is true, the bit about a full-sized dragon is akin to "godly magic" (not talking about alignment here) - it would need an insane amount of mana, a complicated ritual and even the most highly proficient casters would need to pay quite an "upkeep" to keep such a spell going. I guess. On a smaller scale? Sure thing.
(Yes, my vote counts for three)
"Trying awfully hard being funny humble today, aren't we?" (If you are able to pin that quote, It just might heighten your chances...
)
Jokes aside, I have already gathered that illusion is one of the prefered options atm - it woud allow for quite an interesting plot, so I can see why it get's all those votes. Just remember that the "mana systems" are balanced. Mystic plants or other "springs" of mana are somewhat rare, magic is uncommon - but nibbling a good enchantment would keep us on our toes for quite a while and you would need to scare a person half to death with the simplest illusion available to make a profit out of it.
I hope that awnsers all questions - I guess the update will be later in the day as I have some stuff on my plate for now - and it seems that the results could still change.