If he backs up his Electrum wallet file on USB, wouldn't he have to create a fresh backup every time he uses that wallet to receive/send bitcoin? I connect to Electrum through a hardware wallet, so the Electrum generated wallet files have no importance to me whatsoever. I have never tried to recover a wallet with the Electrum-generated wallet file.
If the wallet was generated from a seed phrase, then no, he wouldn't need to make a new back up. He would not be able to save any additional information to the wallet, such as invoices, address labels, or which UTXOs were frozen, but the wallet file contains the seed phrase and would still generate all the necessary addresses. If he uses the first 20 addresses, then Electrum will automatically scan beyond that up to the gap limit. Obviously if the wallet was made up from imported private keys, then he would have to make a new back up if he ever imported a new private key.
But regardless, they way to do this is either encrypt the entire USB stick or create an encrypted folder on the USB stick, and then add the back up to it. Once the stick/folder is decrypted, you can save to it freely before encrypting it again.
I am using two ad blockers but do they really protect against Google-sponsored ads (sites) as well? Like the ones we are used to seeing at the top of the Google search results when you search for an exchange or a crypto wallet.
I don't use Google, but uBlock Origin blocks these ads. It is by far the best ad blocker out there.