To start with quite simple stuff dor DOS: WordPerfect 6.2
or Windows 3.1 programs from 1997 or later:
WordPerfect 7, Adobe Acrobat 3.01
to the more complicated:
Microsoft RDP Client, Internet Explorer 5
Well, why don't you just switch to windows? Win 10 won't run any of them either. In fact, I would be surprised if XP would run any of them. Acrobat Reader, and Internet Explorer 5, are certainly useless, today, but they will run in DosBox, if you set it up properly.
FWIW, there is a new RDP client for OS/2 (RDeskTop), that actually works quite well (it is at HOBBES). It will NOT be included with ArcaOS because of licensing concerns, but it can be dropped in easily. OS/2 has it's own remote desktop (PMVNC) that works well, and it will be included in ArcaOS. The new VNCViewer (also at HOBBES) apparently works with the newer VNC server that windows uses (but I haven't tried it).
That depends largely on specific devices. Nowadays more than before, unfortunately.
There hasn't been a new sound device with OS/2/winOS2 drivers since before eComStation showed up. Now is not the time to try to go back and recover from that.
As long by using heads for thinking instead only for a hat stand there will be no problems at all.
Well, that is not true, at all. Right now, there are probably 6 people who have any idea how to go about writing drivers, of any kind, and they are all busy with more important things than trying to make ancient software work.
So which recent PCIe audio card is supported?
Not enough of them, but most on board sound works, up to about 4 years ago, when the UniAud project came to a halt. I have some Realtek, and Intel, devices that work pretty well, but I haven't seen a plug in card since the days of Creative Labs Live! (which don't work with windows newer than Vista, by the way). In fact I have 4 of those cards (1 is dead), and I do use them in older hardware, with either UniAud, or Sander's driver (one or the other works, but not both, on the same card). They are far better than any Crystal device that I ever had.
Every devoce driver that was certified for OS/2 or doesn't violate the provided device driver interfaces should work usually.
True, but do you have a device that you can plug in to use the driver? Software may work, but if there is no hardware to use it with, you need to take a different path.
Simply not true, I cannot find anything that will prove your claims. And I'm running different flavours of UNIX for more than 20 years.
Sorry, but you need to look harder...
Fake news again. There are no serious relations to manufacturers estabilished yet afaik.
Mensys tried, years ago. They were mostly ignored, and those companies who did respond said "No". If you think you can do better, please do so, but please don't piss off the manufacturers. They are already copy righting their work, to prevent others from being able to use their products (in fact, most drivers are now written by Microsoft). If they do that, and still refuse to make OS/2 drivers (why should they? and they don't do it anyway), we are completely finished. The only path left, is to use whatever some other OS uses, but that comes to an end eventually too.
You are flogging a dead horse. We (the OS/2 community) don't have the manpower, or the knowledge, to do all of those nice things any more. We have enough problems just trying to keep the OS running, and it is getting harder to do as we go along. We have been very fortunate that some people have figured out how to port things from other platforms, and most of that has been on a volunteer basis. Arca Noae is trying very hard to extend the life of OS/2, and they seem to be getting it right, but some things are just going to fall off the wagon. DOS, and WinOS2 are not used very much, and they will continue to work as well as they do now, but they won't be updated to make a few obsolete programs work, for very few people. It is as simple as that. DosBox is a viable alternative. Use it if you need it.