Thanks for chiming in, fzerojones - I can definitely empathize with your situation on Sentence Correction!

One thing I've noticed over the years is that SC tends to almost punish some really-ambitious test-takers who make a point to learn as much "pure grammar" as they can, and in doing so miss the real intent of those questions, which is every bit as much about problem solving, efficiency, etc. as are the other question types.

I'd recommend that you change your focus a bit toward:

1) Look for the major errors that you know come up all the time (verb tense, modifiers, subject-verb agreement, etc.) and train yourself to spot those quickly without letting yourself get sidetracked by more-obscure things (idioms, etc.)

2) Train yourself to shorten sentences by omitting modifying clauses, like this one right here, and adjectives/adverbs so that you're reading fewer words each time and so that the main errors jump off the screen a little bit more clearly.

See how that helps you to make quicker, more confident work of these sentences and I think you'll find yourself solving them more efficiently.