A. Yes, you are over thinking it. It will all make sense after the class. Right now it would probably be good to focus on the meds and doses and what rhythm they go with. Do the AHA practice test a bunch of times.
Look at the algorithm, again, it's not telling you to give 2 meds. If you're at the point you're giving amiodarone, it's not telling you to give another round of epi.
What helped me was, when you do a rhythm check (after 2 mins or 5 cycles of CPR) if you're seeing a different rhythm, in your brain, whatever you've done is null and you follow the guidelines for the rhythm you're seeing NOW
B. you don't actually start an IV, you say start IV. Apply 02, attach pads. It's all simulated on a CPR 'Dummy'.