Creating a private key for a cold wallet and sign all transactions offline

Hi everyone, I wanted to run this by you guys if I am missing something. I want to create a coldwallet and get myself completely off exchanges.

I was told that I can generate my own entropy with https://github.com/iancoleman/bip39 by rolling dice on a pc never connected to the internet and no storage medium. Please let me know if you see any holes in my process.

1. Download debian, verify iso checksums, and use balena etcher to burn the iso to usb
2. put the Ian bip39 and myetherwallet offline html tool on a 2nd usb stick
3. boot up a PC without any internet hardware (no wifi, cable unplugged) and no storage medium. Insert debian and boot. Insert the usb with the bip39 tool. Copy these files to ~/ (which should reside in ram as the pc is booted off a live usb)
4. Roll dice until I get 256 entropy points, select ETH, select 24 words, write down my memonic, and click hide all private info. Hover mouse over first public address generated so a QR code is visible. Write down first 8 and last 8 of first generated public address, then close the page, open the page and type my mnemonic back to make sure i have it correctly written down by validating it creates the same eth address.
5. Open coinbase and send 0.1 eth as a test transaction. Make sure it shows up in etherscan.
6. Open offline MEW wallet, copy over memonic (on offline pc) open MEW wallet on online pc with the public address I sent to in step 5. Follow steps on MEW website to sign an offline tx (move json file onto usb, put usb in offline pc, mount as read only, cat json file and copy terminal output onto clipboard etc). Send 0.1 minus fees back to coinbase.
7. If I am able to sign the tx offline and the 0.1 eth shows up in coinbase it should mean everything is working and I can send all my eth to this cold wallet

I know MEW has a high level of trust in the community and is open source. Should I invest time into getting geth up? Is it possible to run geth and sign a tx offline without running a node (not validator, I dont have 32 eth and would be afraid to run a validator)? Is my process good enough or lacking in any way?