This is really good advice and the coding style (alignment) matches what I came to without any real guidance when I was learning SQL 20+ years ago. The only thing I slack on, is uppercasing the keywords. I hate switching case so much. But, I will fit the coding style of the codebase I am working on when it comes to that.
4GL's were a mistake. We have 4gl code that was compiled into COBOL. Nice. Except, nobody still around knows the 4gl language and the generated COBOL is completely unreadable.
Yup, Z/OS even has an AIX subsystem these days. I have had to use it for some java decryption software and to use it to do some ebcdic to ascii conversion.
You are correct, the OS is patched regularly but that doesn't require a recompile for the COBOL code, the OS ABI is stable and unchanging for legacy code. I have programs still running that hasn't been recompiled since 2005 (maybe earlier that is just what I noticed recently). When they upgrade hardware, they can do it per LPAR. They just shift the workloads over to other LPARS while they are upgrading another. Pretty much zero downtime.
Business Analysts can fit the L2 role. Where I work, they are the interface between the end users and the developers. They usually come from the either the business side or the support center. And if they came from the support center, they usually have prior experience as an end user. However, I can see how that wouldn't work out for all industries.
Started my career doing Y2K stuff in 1998 and I still touch COBOL here and there today. I have a 10,000 line CICS program that runs every 30 seconds that I wrote in 2010. It has never failed since.
On your B) It seems according to 15 minutes of research, it varies a bit on circumstance and where you live but it can be considered "constructive dismissal" in some places. You may be eligible for severance or unemployment if you refuse the demotion. Of course, IAMNAL etc...
DBeaver is the best free (with a paid option) DB client in my experience and I have tried many. I have used it with many databases: DB2 (MVS), DB2(linux), Postgres, ISeries, MySQL and SQLite. Datagrip is better IMO, but I have the JetBrains Ultimate Edition for other reasons so it is "free" to me in a sense.
I agree with everything you said except putting business logic in procedures. That should be in application code instead in my experience. I have worked with too many vendors that put all their business logic in the DB. That always makes things more difficult for maintenance IMO. It may be easy to get something up and running for the first time, but it makes things 10x more difficult to change in the future.
5 minute compile time is annoying no matter what project you are trying to compile. Thankfully most every golang package I compile, takes less than 2-3 seconds.
Java was tacked on to AS400/iSeries so I can understand how it would be painful with any Change/Release management system. I would much prefer to stick with the old crufty RPG/CL on those systems. Tacking on "new" tech to old "green screen" systems is just a bandaid. Should have went to a modern OS at that point. Try doing JSON/CRUD apps on TSO/MVS. Not fun.
Yeah, I have only hiked day trips in Nevada and Arizona in the Summer. I definitely want to try at least an overnight trip in the cooler months or at the higher altitudes. It is on my list of things to do.