Yes, the very nice guy who said he was okay with it, and accepted my offer for eggs when they start laying. He's been watching me build all this time and never said a thing against it.  And now this. It's the wife though, she's sort of a b**** and is fuming over this, and he just nods his head when the two of them are together. Now he says he wants no eggs, no nothing, just get rid of all of it... What a pushover.
I just spoke with the town's animal control officer, who oversees chicken matters in the town. I'm so glad she's answering emails late because I wasn't gonna sleep tonight, I was so furious and sad. She confirmed that the 150 feet thing is BS. The chicken run does not fall under any regulations and can be anywhere I want within the property line. The coop, on the other hand, needs to move back by 7 feet from where it currently is, so that sucks. But the neighbor b**** was complaining about the run in particular, about rainwater draining onto her property from the roof (no, it would drain in the gap I left between our properties, and I was gonna put gutters on it for her, but she'd have none of that), or the smell (told her about litter management, composting, etc. etc. - nope, fell on deaf ears), or looking at it... she wants to enjoy a nice sunny day without looking at chickens (told her I'd put a faux ivy privacy screen on the wall facing her... nope, deaf ears). She was not willing to accept any problem solving and good will efforts on my part and stomped her foot that the run just has to go. 
But in addition to animal control, I have previously talked to the town's building inspector (it's a small suburban town, not a lot of town officials so there's THE animal controls officer and THE building inspector, and that's that). I described it to him and he said the same thing - that kind of structure is not regulated, I can put it wherever I want within the property limits, chickens or not.
So, now I have the official town word coming from both people who have a legal say in this. Both of them say the run stays. I just texted the neighbors outlining the official word of the town. I asked them, given that the run stays, how much do they really want me to move the coop 7 feet. Given that they wanted 150 and to "not smell and not hear and not see any of it", 7 feet is not going to make a difference. It will, however, require ripping up months' worth of hard labor and will effectively put us at war. And I'll ask them to file a formal complaint and wait for that whole process, which will take half a year. So now it's up to them to decide just how much they want those 7 feet.
At least I'll sleep tonight knowing that I didn't dig 3-foot holes into the ground with a f-ing auger for nothing. If they want to look outside and see nothing for 150 feet, they should've bought a house in the woods.