The book is all over the topic of your concerns. It suggests staying far away (at this stage) from the slightest hint that you are forming any kind of neighborhood militia or vigilante team.
Rather, it suggests a very low-key approach, suggesting that your neighbors might look into various options for what it calls a “neighhood protection plan.” The time for this is after your area has suffered a spate of burglaries or other crimes. Baby steps, at first. Find out who is “on board” with a NPP.
Thank those who are not interested, and move on. They are not mentally ready to digest even the baby steps, so ignore them for the time being. If and when the SHTF, most of them will suddenly realize that the NPP was a great idea all along. At that point, these timid types will be joining the already existing NPP as junior members. The very most timid or passivist might not go along with the NPP at all, ever, so you will just have to work around them.
Yes, forming a "neighborhood watch" would be a not-so-controversial first step.
Those who are on board for "neighborhood watch" could then be chatted with about various "what-if" scenarios, like contingency plans for natural disasters. The ones who can't read between the lines would not be people you would want, anyway.
Even those who are not candidates for "neighborhood protection teams" may agree to be part of "neighborhood watch", observing and reporting suspicious activity. It all comes down to seeing what level (if any) they are willing to participate at, and maintaining opsec about activities that they would be uncomfortable knowing about.
I suspected this topic would be key and focus on what pitfalls to avoid. And even a "neighborhood protection plan" might be considered by many as over-the-top. As you suggest, Be civil and move on.