If you want to try making some zero fee txs, check out my project on Github: https://github.com/andersrh/Wallet (fork of the Bitcoin.com wallet code)
What if I make first a zero fee tx (hopping for some pool to take it) and then double spend the same coins with 1sat/byte so that it's ok for 0-conf ? Can I double spend that way ?
You won't be able to do it in the wallet but if you import it in another one like Electron Cash, you would be able to double spend it.
