Hey Tarmac,
great score, congrats! I feel I am in the same boat as you in regards to scoring 41-42 verbal with time remaining. I do agree that I think spending extra time on verbal is essential and that every "keyword" has meaning, such as extreme words, can't, all, none, or iffy words, some, most. I think those are huge in doing well on CR, and RC. You can eliminate a lot of choices by identifying those types of constraints. Also with assumption questions, you really can't stray much further from the argument. The assumption should be easily identified from the argument, using similiar language. Make sure the things they are referring to in the question or stem are the same things you are talking about in the answer.
So if the question talks about widgets, the answer should be about widgets, not about things closely related to widgets.
How long did it take for you between your Gmatprep of 710/730 until your 770 gmat prep?