P: Ability to arrange & customize save-as file formats so popular formats are at the top

Your post does not seem to be useful. 

• First off: Adobe and the Photoshop team are not obliged to implement Feature Requests, no matter how popular they are or how long ago they have been made or how well their potential benefits are presented. There are people that have taken note of the request but the decision on the issue may ultimately not be the one you would prefer.  
• Secondly: One can restore the »default-non-proportional-transformation« in Photoshop; see »How do I turn off the new proportional scaling by default behavior while transforming layers« on this page: 
https://helpx.adobe.com/photoshop/using/free-transformations-images-shapes-paths.html
• Thirdly: Photoshop does not feature a »Transform Tool«.

While you may call that last one nit-picking, if one does not respect the meaning of words and the use of proper terminology in written communication then what is one even trying to do?

Ridiculous comes to mind...  8 yrs and counting, meanwhile they found the time to fucjk up the free transform tool just because they could.

Methinks Adobe know they have us by the short and curlies with this dumb subscription model, and they really don't give a flying fwhatever about the people who pay their wages. And no good pointing at Chris, he went ages ago.

Has Adobe exhaustively researched the options for implementing this change?
They can't find time to do it, in 8 years? 

Why do I need to learn to coding/scripting, when Adobe has people who do it for a living, who can knock it out in 1/100th of the time I could, and fix the problem for everyone, not just one guy?

And let's not act like Adobe strictly prioritizes based on popularity/"me-toos" - many ideas with fewer upvotes than this one have been implemented.

The ability to auto-save was proposed 8 years ago, and only got 23 upvotes. Various "Champions" (including you, Chris), argued about how it was impractical, ineffecient, it should be the user's responsibility, etc.

Less than a year later, it was implemented, it works fine, the handwringing about it was completely overwrought. It was an obvious, common sense change, and they just did it.

Now we are faced with another obvious idea, and it's so frustrating seeing people perversely argue AGAINST it. I guess some people just have that kind of mentality.

Microsoft word has had the ability to set a default save format (along with a logically ordered save-as dropdown) FOR OVER TWENTY YEARS.

https://i.imgur.com/M75eX2i.png

Sure, this is not one of the big problems with PS, but it's also not as hard to fix as the awful performance even on the latest machines either. And having to write a script (I did do that actually and posted my script here) to circumvent something as simple as saving your files is not a good way to design user friendly software, right?

Well, the number is still not quite »up there« with the »most popular« requests. 

And while naturally everybody who supports it (and possibly many, many more Photoshop users) would benefit from an implementation for many other users it is effectively irrelevant. 
Photoshop offers options for customisation and automatisation that make it possible to pretty much circumvent the Save-dialog for saving copies off of the layered files one works on. 

To put that into context, the highest rated idea for PS hast 232 votes, and it is to do with organisation of presets. The second highest rated is 175. So it's not like 33 is a small number. But the reason everyone keeps coming back to this tread is because it's a good illustration of how clunky and out of touch Adobe is. This is indeed not the sort of problem that breaks the app or makes your life miserable, but at the same time, there are just two possibilities:

1. is that they can't change this because of how old the software is and how little control they have over it, in which case, it makes no sense to keep hoping they will ever get better.
2. is that they are simply too out of touch, which leads to a similar conclusion.

Well ... 33 votes seems far from overwhelming support for the request. 

Saving to particular formats can be streamlined with Actions and, considerably better, Scripts as it is. 
Have you looked into those options exhaustively yet? 

I don't get how it doesn't have more traction after so many years. Looking through the ideas I see stuff like "custom colors for guides" and "saveable grid sizes" and I totally get there are a few people who use those features every day. But literally 100% of photoshop users use the save dialogue.

Are they ALL really ok with saving .png's by clicking off the filename to the filetype dropdown, tapping P, tapping down-down-down-down, clicking back on the filename, typing the name, pressing enter, pressing enter again to confirm the same old save options that they never change?

This is starting to feel like a yearly event where someone posts a new comment in this thread and we complain about how bad Adobe is a bit more. Maybe it will evolve into a formalised meet-up or conference at first with people originally on this thread and later with dissatisfied customers the world over.