They are somewhat vague. We've made threads on how summoning/creating magical things should generally work. However, part of the vagueness is intentional on the part of the game designers: the narrative impact of making a chainsaw gun using your Craftsmanship skill, or a stone golem using Thaumaturgy, is going to vary between gaming tables - and maybe even between sessions in the same campaign - so it is intentionally on the players and GM/referee to agree on how to do a particular thing.
A lot of us are used to incredibly detailed point-based systems (like HERO) or systems which aren't necessarily (or transparently) point-balanced but are fairly codified (like D&D). And as such, it can be a challenge to come to such a free-form system like this and try to negotiate balance, but that is the strength as well as the challenge.
So, to your Thaumaturgy question: There are 2-4 ways to acquire items and/or personnel in this game.
Resources: I buy the item. Player outlines what it does. GM establishes a Quality which becomes the difficulty to acquire the item. You could use it to justify buying the services of personnel, and again, the GM establishes a Quality to that transaction.
Craftsmanship: I make the item. Player outlines what it does. GM establishes a Quality which becomes the difficulty to make the item. You sort of need Resources or a Stunt reflecting your workshop in order to make it, or you can borrow someone else's Resources to get it. Not easy to justify acquiring personnel. Edited to add: Unless you have a Stunt saying you can make mechanical personnel, which would be basically using Craftsmanship instead of Resources/Contacts.
Contacts: For getting personnel, this is the best skill - again, the GM establishes a Quality to that transaction, which becomes the difficulty of the roll. For getting items, it could also be feasible to say that you get the item from someone. Player outlines what it does. GM establishes a Quality which becomes the difficulty to find someone who can get you the item.
Thaumaturgy: You make a magical substitute for an item or personnel. Player outlines what it does. GM establishes a Quality which becomes the number of Shifts the spellcaster must summon and control to make the item or summon the magical being which will end up doing the job you want. In the book, Summoning is referred to as simply a magical Contacts roll. Item creation could be a magical Resources or Craftsmanship roll.
Ultimately, Thaumaturgy can do anything any other skill can do.