So my question, going off the book would it be more acceptable to be capable of something like that if you had fire as one of the elements you're specialized in concerning evocation? Does what you take with one affect what you can be good at with the other?
It should be technically just as easy for a fire-specialized spellcaster as a water-specialized spellcaster, so long as they both have full Thaumaturgy.
That said, wizards can get theme-related focus items for Thaumaturgy. Traditionally, you buy focus items (YS 278) to improve Lore or Discipline checks for a given
Type of Thaumaturgy: Wards, Veils, Summoning), but the rules (or RAW as you will see it on the boards here) also say you can do it by
Theme (Biomancy, Ectomancy, etc.).
So, it is plausible that a fire-themed Wizard could *also* have bought specialization in Fire-themed Thaumaturgy as well as Evocation. And this wizard will have an easier time doing fire-themed rituals.
Also, a fire-themed wizard *may* have an Aspect about his use of fire magic which he can tag for a Fate Point during the ritual process, which can be an advantage.
But other than these two options, no difference in difficulty.