Is Hardware wallet + Google auth still sufficent for security?
Yes, this is suffice and can remove your worries if you want a safe storage for your cryptos.
I hear that you can make passive income staking via this new Defi thing - Anything more i should know there?
On hardware wallet like Ledger Nano X, you can stake the supported coins that they have. You don't have to through with any DeFi.
What is the new hot coin to hodl?
Never gets old, bitcoin.