I downloaded the BTC blockchain and created a couple of wallets with the new version on a USB hard drive.
I would recommend against using USB drives for the blockchain. You are more likely to run into database corruption errors and accidentally corrupt the database by prematurely unplugging the drive (as you have done).
I'm hoping that my wallets are still intact after recovery.
If you are able to start Bitcoin Core with those wallets, then the wallets should be fine. Of course, you should double check that the private keys are correct by signing and verifying a few messages with your addresses.
I have two workers pointed at those wallets so I am curious to see if the coins mined during the down time will be there.
A wallet does not need to be online in order to receive Bitcoin.
I also wonder what happens if I ever shut down the node on purpose. I am assuming the wallets will be there but will I have to download the whole damn chain when I restart Core?
Bitcoin Core requires downloading and verifying the blockchain to work. The blockchain can be pruned, in which case blocks are discarded after they have been verified and area few hundred blocks deep into the blockchain. If you do not have a copy of the blockchain, it will need to be redownloaded.