Job lore and reworks

[YianKutku]

While Thaumaturgy and Conjury seems to manipulate the basic elements for quite raw effects

Not necessarily. Thaumaturgy, for instance, is capable of much more than simply blasting stuff. The offices of the East Aldenard Trading Company in Kugane are warded against eavesdropping via thaumaturgy; presumably Lolorito hired the Thaumaturge's Guild for that job.

We as players simply don't see the various uses of all the schools of magic, due to game mechanical (and game design) constraints.