What are my prospects to get a Postdoc position with just 1 publication from PhD?
Except for the difficulties in getting your advisor to respond to you, nothing you say seems unusual. Even that is too common, though. But your age, etc. is pretty typical, or at least not far outside the norm. 

But I think that if you can unblock the block that you will be in good shape career wise. Your difficulties with industry could be a lot of unrelated things, and you haven't really tested yourself yet in the academic marketplace. 

If you want a career in academia, I suggest you start a search, either as a post-doc or a regular position. You have a lot of work-in-progress to point to which is a point in your favor. I wouldn't wait until you get the block cleared and then something submitted and accepted. It will take to long, but, I suspect, not be judged fundamentally differently than work in progress.

The only issue I see is your "out of the mainstream" research interests. You will need to find a way to present that as an advantage, not a disadvantage. As Apple used to say, Think Different. 

There is, I think, no reason to do the two things sequentially: advisor, job-search. Work on both in parallel. 

On the advisor front, however, you might want to make it more incremental. Rather than "all these papers", focus on getting just one out the door and then repeat as needed.