my second mage character was exactly like that. i had conjuration illusion and lightarmor and archer as my only major skills.......aside form enchanting and smithing which always get levelled up for me in every game because im a loot hoarder. i agree that its a blast playing that way and on top of using illusion and conjration spells i would dual wield staves and i had some epic battles. i just wish that i had my scamps, clannfers and cuddly daedroths back though. thankfully mods will fix that soon enough.
My character does use a bow (much more sparingly in the past 10 levels in lieu of staves).
I wear only robes and boots. Unfortunately the dragon priest masks are light armor (I still use them).
Heh, I'm a bit if a hoarder too. So often limping along to the nearest town, overweight. Trying to find animals to kill, load with loot and reanimate.
I am all for more options to support differing play styles. I do like how they require a corpse for necromancy. I don't like different spells needed for different levels though.