Some notes, a basic check indicates you didnt make any mistakes.
It looks to me that, by math as written, the Thaumaturge is losing in total damage as compared to every other Martial listed, or is very close. In those cases it is close, that is because unlisted is a major trait that the Thaumaturge does not have an equivalent to being unused in the comparison.
Dual-slice, power attack, familiar precision damage, all effects that the thaumaturge lacks an equivalent to. Nothing wrong with this, of course, the thaumaturge is then slightly behind all martials with a more more consistency and a bit more of a specialty in one-action strikes. Its a unique sort of damage pattern, but very much within 2e standards.
So, if the class is balanced as a martial, it seems to me that adhering to the martial baselines like this is doing makes a lot of sense.
I dont "love" that 2e has these strong baselines with little deviation, but looking at the math here, its at least a distinct way to go about it, and is well within the norms set by the class. Rather than hitting hard, the damage is because your attacks 'burn' into the foe. Its not haymakers so much as salt on giant snails.
Ultimately, utility effects and disables are very guarded, but accessible to *every single class* as part of that. I am not sure it would make sense to try to rebalance the class towards that given the game's core principles. So, what else is there except damage, and damage expressed in a somewhat unique way?