you don't need the tech capacity to do it offline you just need to do a copy(backup) of your wallet data and put it in a usb , that's it, then only plug it in a secure environment
i would not recommend using any online wallet, minus maybe coinbase
Sorry but that would leave your private passwords online where malware might steal them.

what you mean? coinbase have insurance against thief, so even if they are hacked they will cover all your funds, not like other excahnge that they will try to bring up any excuse to justify the hacking
Insured against outside theft. You will find that insurance companies do not cover embezzlement, which is how most theft of online wallets occur.