1 – I think your fireman neighbor is being very honest. Treat him as such (maybe thiking meat on the hoof if your mind wanders in that direction).
2 – Your deputy neighbor is stuck thinking in terms of what is, not what probably will be. But he probably can be talked to. Cultivate him.
3 – By fuel storage bunker do you mean one of those big-azz LNG/propane/oil tanks? My advice is not to do anything to/with/about it except plan a) how to drain it into a more secure tank; and b) how to booby-trap it. In the mean time, start planning on how to replace it with one built underground
4 – as for “opsec” – first, stop using that term. Second – stop bworrying about who locally knows you have fuel stored and start thinking about which of them might be likely to try and come take it away from you. I’ll bet not many will want to risk anything and that will just be a pest and beg for some.
5 – If you do not like “everybody” being able to see what you have as they drive by, mask it. One of the cheapest/easiest/fastest things you could do is build a pole barn around it.