persp-projectile VS crux

I am currently trying with perspective rather than persp-mode, as it segregates the buffer list as I like (#1 above). I've got projectile with persp-projectile, and that seems to give me what I need for project navigation (#2 probably, still not 100%). I get some help in my mode line for project focus (#3, partially).

Aye. I often have two interdependent projects I work on simultaneously, and I use a lot of persp-projectile (https://github.com/bbatsov/persp-projectile). I would love to try project.el but sadly it seems like it doesn't integrate with perspective.el yet.

I also use purely emacs for "commercial programming" (as you refer to it) and for managing multiple projects I use projectile + perspective + persp-projectile.

I had my own rolled version of this in my config until recently when I swapped to perspective and perspective-projectile.

For those still on 28, crux-rename-file-and-buffer does the same thing (https://github.com/bbatsov/crux). I've been using it for half a decade at this point. This sort of command, that no other code will rely on, was never that important to get into core, and there's some merit in making people create the commands they needed. It's not like with the additions to subr and subr-x libraries (string-replace, string-search etc), which can't come fast enough.

Use vc-rename-file or crux-rename-file-and-buffer from crux

A similar functionality is in the crux package (see crux-delete-file-and-buffer).

How about https://github.com/bbatsov/crux?

Some packages I use for more effective text editing is crux for general text editing (video on crux), paredit for lisp editing and for org-mode:

I'll go with crux. It's not all about text editing, but it's got a lot of commands in dwim-fashion.

I learned the syntax of org-mode in an hour (maybe less), It has many superiorities to markdown (see this excellent essay). Emacs is a fully-featured tool, it's a lifetime of learning, just like all extremely powerful tools, you can see the blogs of many emacs experts like Bozhidar, Protesilaos, Karl Voit (to name a few) learning new features of Emacs quite regularly.