I'm actually excited to play a Thief Rogue!
With 1 level of a caster class, you'd get access to their scrolls (and can create cantrip/lv1 scrolls on your own, to feed to your bonus action habit). Though, as using higher-levelled scrolls than you can cast is at best a 50/50 roll (d20+casting stat vs DC 10+scroll level), it's best if your character concept incorporates rampant wastefulness and high-maintenance lifestyle as a core part of your identity.
I like how the Thief is just adaptable - you could be the support caster of the party if there are no other casters present, and that level of a caster could be Wizard for the widest selection (and True Strike + Readied True Strike shenanigans), or Cleric if there already is a Wizard in the party (no-one would object to you crafting Blesses on demand)... or even a level in both to cover all the bases! And if someone else happens to grapple/Entangle a target, then you can decide to save on resources and just slip a rope/manacles on them.