if you can do research now do it. Because you will need it for a plastics residency. Anything that makes you look better than other people is a huge plus.
also, I don't see the harm in reading pathology books and reviewing biochem/micro stuff (medical student type study books). You don't need to sit and memorize crap now but honestly if you don't mind reading them a few hours a day it can only help you in the long run. I don't suggest board studying now but general text book reading of stuff you will see in your classes will put you at an advantage.
Personally, being in 3rd year now that is what I would suggest. There is just so much stuff out there and you can't remember it all. It seems to take like 3 times to see the material before you really start remembering it. That's why reading/light studying now will go a looong way in the future. If you can research now also do it. If you can shadow a doc who will teach you stuff now (so long as you are reading up on some path) do it because it will help you in the future. You can learn basic stuff now like how to take an HPI, how to present (it's not hard btw), how to do basic physical exams, etc etc. This stuff only helps you. There will be people in your class of varying experience levels and since you want to do currently the hardest specialty to match you must make yourself look better - and this is coming from someone who just wants gen surg with already a good step 1 (230s), decent grades, etc. Med school is hard but the harder you study the easier it is in the end. For example, if I could go back and study step 1 again I would destroy it... you know why? because I have already studied it hardcore for about 2 months; give me another 4 weeks even now and I would destroy it because I have seen many patients with diseases discussed and studied the material over several times through clerkships. So yeah studying now will not hurt. Personally I wouldn't waste the time since you want plastics. Now if you just wanted family med or internal med that's different. But derm, plastics, etc you need to be the tops in your class consisting of other very smart people. So that's just what I would do if I could do it again (I didn't take a year off b/w but this is just my advice since you have the time and seem willing to actually do it).
