Another thought on the systems finals, take the final exam twice, using every minute of the three or so hours you get.
Start with the questions you know. Zip. Skip any you don't immediately know the answers. You're at least in the 70s. No go through and do the calculations. 75%. Now go through and do the ones you have to think through, skipping those that you really don't remember. You should be in passing territory for sure, so you can relax and take another crack at those that you have to look over the systems diagrams (for CRJ, don't know about the option for the 'Bro). Now go through and take the test again, beginning to end. If you come up with a different answer, mark it. After finishing the second complete time through, come back for the last time and check those you found a different answer. Chances are your first answer was correct. Think you way through the system and then, turn it in!
Just knowing that you are going to spend the full three hours to take the exam slows you down and lets you RTFQ and RTFAs, saving a few face palms during grading.
Good luck!