While it may come off as bias, I believe the bigger interest should lie with fixing core emulation issues like those mentioned above, before all the different 'unofficial' attempts to try new video/audio/controller tweaking. Just my two cents...probably worth less in most places, and certainly people can spend their time doing whatever...lol.
Still, the sound should be considered a high priority issue and it should be fixed as soon as possible. The sound desyncs and crackling have been a rather nasty problem on all PCs I've tested that met or have exceeded the requirements. This has been a big issue since 1.37 with the prior releases not having this problem. I think it deserves looking into before anything else, but I do agree with your view on video and controller tweaks mostly from the fact that it's not necessary to mess with something that's not even broken.
Also, you commented on posting Marty's information as being rude and selfish. While I can understand and sort-of want to agree, you have to admit that it wasn't too polite of him to drop-off the face of the earth without saying a word, either. I think a small explanation is in order. Aside from this, I do appreciate his work and I have the utmost respect for him, and I hope he returns to the emulation development scene one day.
There's are a few things I can think of that need to be fixed respecting Nestopia core emulation issues:
2. Ninja Gaiden - During the intro animation-story graphic color glitch of the moon in the lower left portion. Also reported...
I think I reported that issue a good while ago and soomeone replied that wasn't a bug.
As for the future of Nestopia, I was hoping R.Belmont would take the project under his wing in Marty's absence.
It is indeed an emulation bug. I used to own the cart along with a real NES. This bug never happened on the real thing.