Then you’ve come to the wrong party. Fairphone’s unique sales points are fairer mined minerals, fairer factory conditions and repairability. That’s not story-telling, their results are observable and quantified in their reports. Indeed they offered the Open OS as an alternative OS for the FP2, but that was not part of FPs mission and not a promise for future phones either. Don’t get me wrong, I care about privacy, as do many others on these forums, but privacy is not what FP tries to sell.
With that one sentence, you yourself have already reduced the top half of your essay to a variant of “Fairphone offers X, I didn’t listen and expected Y, now I’m not getting Y and blaming FP for it”. I don’t think FP deserves the label “deceptive” for that.
As for the second half, it is genuinely sad to see that you had so much trouble with the hardware. I’ve had my fair share of trouble, but luckily all within warranty. I can understand that this reflects badly on your experience, as it definitely reduces the durability argument to a flimsy one.
That’s cool, that’s completely your choice! 
But if you ever change your mind, make sure to monitor this thread. I suspect this is the first step in bootstrapping LineageOS for the FP3.