Yes it is still good and Yes that is the correct GitHub repository. However I would recommend using a better method to generate a paper wallet. My suggestion is using Electrum, and here is why:
1. It doesn't run in your browser and it is not written in JavaScript which are both two big advantages
2. You can generate both individual private keys (generate a new wallet then export a single key) or a mnemonic which means you can have many addresses derived from it which solves the address reuse issue with paper wallets with a single key on them
3. It is a well known wallet used by many and it doesn't have any bugs when it comes to key generation.
but am curious if a VPN and TOR would make paper wallets reasonably safe...
You should always create the paper wallet offline, so there is no usage for VPN or TOR.