there is a saying : no pain, no gain.
let me rephrase it : no btc, no pain
just sell this s*it and put all earned $$$ to the bank. now they are safe.
but seriously, man, do you have quite a lot of BTC to ask questions how to hold it? I'm sure that if you'll choose to keep your crypto on exchange - just use the google auth for your safety, and those idea for splitting - is just wise. Put some of your BTC to PC without internet and back it up often , the rest for trading on exchanges
I guess that is good enough