Trying to create a bitcoin public/private key using bitcoin-core
If you are asking about the bare minimum thing to store to ensure that you can send and receive funds, then it will be the private key (which you already know). But to make transactions via the core, you only need to store the private key you get from the dumpprivkey api call and the address for receiving funds.
To receive funds you have to use the address.
I am unaware of any core API which would give the hex value from the private key you get from dumpprivkey. However, it is a really basic encryption scheme and you can decode it back to hex using any programming language.


This would be useful for a detailed explanation.