One thing I just want to clear up. Nothing above was wrong, but could be misleading.
For ATW's, IF they list boundaries on the ATW, then you can fish outside of those boundaries. But many/most ATW's do NOT list boundaries. And in those cases, the entire stream is ATW, and thus off limits. Which includes any areas that aren't stocked. Yellow Breeches is a fine example. With the exception of the special regulation areas, the entire stream is ATW, and thus off limits to fishing, whether or not that area is stocked.
1. All ATW's are off limits. Again, unless otherwise stated, if listed ATW, the whole stream is ATW, not just the stocked areas.
2. All special reg areas are open, follow posted regs for individual stream.
3. For unlisted waters, there's been a debate every year, mostly about whether you have to use the "chub defense", and IMO the PFBC should make this a little clearer. The general consensus is that they are open to C&R trout fishing. Someone always ends up posting a link which makes it a little more clear, wish I had that link. The extended season doesn't even apply to these areas. The harvest season ended on Sept. 2, it's all C&R from that point forward. And March 1 holds no significance over Sept. 3.