The Focused Practioner takes at least one (1) Spellcasting talent; Rituals (-2), Chanelling (-2), Evocation (-3), or Thaumaturgy (-3). So, you take your minimum True Faith powers (-2), and Thaumaturgy (-3) and you're good for a feet in the water-level campaign. More refresh/higher power campaign means more powers, more stunts; or just more Fate points at the beginning.
If your GM will let you take Rituals with the focus of Banishing, then it's only -2 Refresh.
Anyway you look at it, this is a quite reasonable starting character for DFRPG.