I only buy something once every few months. I purchase my BTC with a credit card, and send it to a secondary wallet. Then I send it to a wallet on my main computer. Sometimes I juggle the BTC between a few different wallets, but I'm aware this is kind of pointless. Finally I send it all over to my wallet on whatever site I'm going to use (usually divided into two amounts if it's over $100). When I installed the Linux distro I currently use I encrypted my hard drive (but not my home folder).
So after reading the method I usually use to get my Bitcoin to its final destination, do you think I'm being careful enough? Should I be tumbling?
well that's all a waste of time. tumble them.
ditto
pretty much the only useful thing to encrypt is your home dir
you've done absolutely nothing to protect yourself from Coinbase getting subpoenaed or from your computer getting siezed. if you're ok with that, great. if not, do things better.