I've been in pretty much the same situation as you... went back to school, working two jobs, taking care of two places, 9 horses and two large dogs, then decided to undertake a sizable building project... pretty much by myself. Pretty much complete now (literally a couple minor things to finish up) but, along the way I heard many comments from relatives, neighbors an coworkers about why I didn't just git r' done...
My reply was usually something like, "when you build YOUR shop, you can build it any way you want"... and that was pretty much the end of the discussion. I don't have much time for negativity.
You are building your shop with the method I wish I could have used... as far as the super-insulation is concerned. My building is fairly large and I'm pretty sure I wouldn't have had the time or the money to build that way though... what I do have will work for me...
I've read your entire thread and think you and I have about the same level of OCD, but i prefer to call it attention to detail... lol. My theory is that I would rather take the time to do something correctly and be DONE with it instead of later having to redo something or wishing I had done a better job, etc. Too much time and money invested to not be satisfied with the results. This building is something you'll have for many years to come and I'm sure that, in the future, when you're working out there, warm and comfortable, you'll be happy you took the time to make things "just right".
Keep fighting the good fight... you're nearly there!!!
...D