Offline BTC Wallet, is this correct?

Hello,

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I'm new and I want to ask you if my idea is correct or not.

* Brand new laptop

* Brand new USB Key

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1. Formatting the laptop using OFFLINE setup, NEVER connect it to cabe or WiFi, NEVER.
2. Installing BTC official wallet using the .exe, downloaded using another PC and moved in using the USB Key.
3. Creating a wallet and writing on paper the seedphrase, here the question: can I create a wallet without being online? Or must be connected at least for few second to be created for real?
4. Sending BTC to the receive address using another computer.
5. Literally destroy the hard disk.

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According to my idea this WALLET must be 99,99% safe, it is correct? Also the "offline wallet creation" part?

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Thanks for reading :)