I might be missing something but it sounds like your workflow is full of edge cases and unusual requirements. There's some valid criticisms in there for sure but I wouldn't expect most products to address many of these.
Don't blame the user for Gcal's inconsistent and hard-to-internalize mental model.
Try not to give reasons to discard someone's feedback, and instead identify the core issues which, if addressed, would benefit multiple users.
It doesn't matter how many people are stymied by poor behaviours, if they are the ones making recommendations to their contacts or businesses on what support could tracts to sign…
Consider that statistically if there's any one person having a problem using software run at that acale, a significant number are likely exist with the same problem without speaking up about it.
That's where the opportunity is.
On a related note keeping the same thing in mind with software that you're building is a very powerful tool: "it works for me/on my machine" is great, but it discounts the possibility that if one user is seeing a bug or usability issur, chances are that that others are too - and not talking about it.
