I completely agree with just about all of this except #5. I think modular is absolutely stellar if you have don't have a clear direction or idea of what you want to do musically specifically BECAUSE it is a sandbox. The caveat to that, of course, is that one must be comfortable with experimentation. Maybe that's what you mean by having a developed direction, I am not sure, but modular is definitely not for you if experimentation is not something that appeals. Besides, how does one develop or come to recognize limitations without experimentation? Modular, to me, is one of the most suitable milieus for this.
Yes, it is expensive, but, as you say, with a little research one can learn synth basics and start small, and let the system grow organically along with one's musical/artistic direction. A professional-level bass or guitar, amp, and minimal pedalboard can add up to several thousand dollars. If you're a drummer you know how much a good set can cost, especially when add quality cases. As an upright bassist, I can assure you that quality student-level instruments can routinely cost upwards of $5k. So, put into context, modular isn't actually that expensive unless, as mentioned, you want to replicate a Moog One. Which I would agree is utterly insane.
Inscrumental music for prickly pears.