A Beginner's Guild to Obtaining and Sustaining Fuel
Minor corrections: Your own gas pumps harvest every other day; not every day.
The only fuel item in the craftshop is the fuel can. Other craftshop items cannot be traded for fuel.
7A. Also snag sample craft goods to trade for fuel.
7B. Sometimes the eggs neighbors post from their chicken coops (and any you collect by clicking your neighbors' chicken coops while visiting) will yield fuel refills. I think the same is true of bunny eggs from the feed
You can get fuel using the fetch button in the doghouses. Make sure you have 6-14 treats in the house - more gives a different set of prizes - and 'fetch' will get you a random consumable. Fuel, fertilize all, animal feed, water can, or flower food.
The free play on the prize machine gives fuel sometimes.
The 'get crafty' leaderboard challenges usually have fuel as the prize for reaching certain numbers of goods. Both craftshop and spa/winery etc goods count for the challenge.
Be sure to harvest your Imperial shipyard and Mountain palace; you might get fuel. (I can't remember whether the same is true for the Hawaii volcano or HH mansion.)