many of the would-be PMDevers fall by the wayside discouraged

This is definately the case for me, for most of the reasons that you mentioned.

At one point I had a problem with seeing duplicate posts. I did not want to the that the node had been reaped by NodeReaper in Newest Nodes, I did not even want to know they existed.

Fortunately Mr. Muskrat had some code that he let me look at. He wanted me to try and patch it and see how I did it. I have never been completely satisified that I use the "best" methods of getting things done, but gave it a bash. My problem was that I could not test it. So I had no confidence that it would do the job. In the end we both came up with a very similar solution which was implemented.

Without being able to see how things sit together and interoperate other potential PMDevers will be less inclined to even try.