hackers are overrated, dont complicate it

let's say I only want to save my money in a cold wallet, never make a transaction or sending anything.

you guys tell me if this is safe or not.

- I download Electrum from the real website to my laptop

- before I install it on the laptop I turn wifi off, bluetooth off, basically putting it on an airplane mode.

- I create a wallet, and save the 12 words (on a paper or plate...etc)

- I save the public master key on a note file or copy it any other way.

- I then unistall electrum and delete the wallet file from my laptop

- I turn my wifi back on

-I reinstall electrum and create a hot wallet (watch only of course)

Is there anything a hacker can do about this unless he is a wizzard?