I can't comment on the strategy for the Kim books. But as far as test mentality goes, try to think of it as 4 smaller quizzes that you need to get an A on. It's a lot easier that way.
This is a really good way to go into it. Have you ever got 25/25 on a test in UG? My money's on yes, so all you have to do is do that 5 times within 4 hours.
Also mentioning stamina, I still remember sophomore year I had three, two hour finals back to back to back. It won't be that bad.
I 100% agree with this mentality. Mediocre, as for approaching the balance between reading and studying, I would usually read a couple of chapters a day and put post its on the pages where the book had drills. After a couple of days, I started making progress in the book and would go back and take some of the drills I found to be relevant. Obviously, do more of the book drills in the beginning to get the fundamentals down, and taper off to un-timed sections, and then eventually timed sections. It really helped me stay on track with the reading, but didn't waste time doing basic drills for concepts I was comfortable with. If you are in an absolute time crunch, use the method I laid out above and only go back to take the practice questions with explanations, not the mini-drills. This will teach you how to recognize the wrong answer and hopefully give you an idea of where you need to go back and concentrate on some of the more fundamental principles. I can't attest to the Trainer, as I haven't started it, but I found Powerscore LG bible to be very useful, and in combination, the LR bible and Manhattan LR to be solid. Just finished the Manhattan RC, and it was a surprisingly quick read.