Rotaries are better/easier. The lamentation I hear from the manual guys is that it takes a tiring half hour to tank up. For cache fuel, one would work just fine. You likely won't be in any hurry to fuel up in a dystopic future. They're tagged at 10gpm, but only if you're 6'4" and athletic buff. Buy two, they're cheap. In a dystopic future, two is one and one is zero. Or buy 4 and sell the other two for food.
You'll double your investment cost if you go with an electric. Northern and HFT both have them, $99 and $129 respectively. I'm optimistic and would trust either.
Absolutely. The cheapies come in the kits, or buy a really good one with water separator. I put a nice Racor on the diesel tow truck for an employer a couple decades ago.
Get backup bung wrenches, too.