This is my opinion/two cents on these subjects:
PAT: While some books like Barrons may be helpful, I found that doing well on the PAT for me required practicing with CDP. I completed 7 tests from CDP and I believe they prepared me extremely well for the test and well worth the time and money. Obviously, to do these 7 tests took 7 hours, so if you wanted to take this route I think it is entirely doable.
Side-Note: I didn't have any half hole punches on my test but multiple hole punches on the same problem are entirely possible.
RC: I would definitely practice this section on practice DAT tests rather than journals. I would also try several different strategies to find out which works for you. I found that reading the passages before answering and looking at the questions worked best for me, but I know some found other strategies more effective. Try several and decide on a strategy for the test. Oh, and I would definitely practice all of these tests timed, because time is an extremely important issue, and it will help you develope a good pace.
Science: From my own experiences, which could work differently for you, I believe you will be o.k. in gen chem and o'chem if you just review and know KBB. Definitely know more than KBB for biology however.
Grading: AA is average of everything but PAT. TS is based on number correct out of the 100 total science questions on the exam (not an average).
Hope this helps and good luck!