when PADI started allowing rescue (u/w recovery of conscious/unconscious diver) into the OW program?
I think you have to go back and re-read what he said. He said "ELEMENTS" of the rescue course, like establishing positive buoyancy on the surface (which is an obvious discussion point for the CESA) and dealing with a diver in distress on the surface. The tired diver tow, for example, which is in confined-2, is arguably a "rescue" skill as well.
Can the instructor test/evaluate this as a mandatory requirement of the OW program (required for certification at his/her election)?
I think it would be substantially exceeding the scope of the OW course to teach controlled buoyant lifts during OW. At the OW level, divers are still getting a grip on how to make a proper ascent themselves!

If you felt it was necessary, however, you could do it.... but you would have to sell the students the OW, AOW and Rescue courses as one package to teach them all of the rescue skills. It would also result in the student being issued 3 cards, not one.
But I already told you that and it seems to not be sinking in.
How about tide tables? If these are required for safety in the local diving area, can the instructor test/evaluate on these as mandatory for certification? Again, when was this changed?
I deal with that in OW because it's necessary to ensure that OW divers can find the "slack" times for planning dives (or at least for knowing when they *shouldn't* be getting in the water. Some of our best local diving is in tidal waters so they need to know. I was also taught this in MY OW course in 1984. Nobody wants newbie divers getting caught out in a current they weren't expecting! This is just something that's necessary for local diving in my area.
It was my understanding that in 2010, all buddy breathing was discontinued. Is it still valid at the DM level under the new Standards?
yes
When I was censored by PADI HQ, I didn't think anything in the Standards prohibited these things as well.
You're confusing two different things. If I understand what you said about this, you were teaching pretty much the whole rescue course in OW and not giving them a rescue card or sequencing the courses OW, AOW, RESCUE like PADI perscribes.
I think this fell along the line of what Peter Guy was saying; as you can embellish the standards to a degree, but can't add anything to it that's not specifically mentioned.
Unless it's something that is required for local diving.
I've given you a couple of examples in previous posts. A basic handling of gas management is required by an EU norm where I live and it's not in the standards.
Likewise with teaching drysuit if the checkout dives are going to be done in water that's too cold for a wetsuit.
But I've told you this before too and this doesn't seem to be sinking in either.
deeping-out (embellishing) is a grey area. Adding a substantial part of the rescue course to OW changes the scope of the course to such a degree that it clearly isn't "embellishment" any more. I'm getting more and more of a sense that this is what made you so cynical 18 years ago.
What I can I say... you can't just do whatever you want. If it's so important to an instructor to re-write the standards to suit his/her personal convictions then clearly the system isn't for them. But that doesn't mean the system doesn't work. That's black and white thinking.
R..