OP--I agree with pretty much everything everyone, including you, has said--even if it sounds contradictory. And I thank you for having the guts to post because I am bringing my parents this coming January and even though that is only 2 additional adults, I'm a bit terrified. I'm the planner of our crew, as is probably obvious based on my DISboard post rate, and my parents have been to WDW once, 20 years ago. We stayed at the Swan or Dolphin, or maybe both, in a comped suite related to my dad's conference planning work. They remember the whole thing as totally magical. My husband understands DVC and the risks and rewards but he definitely always has high expectations and is affronted when our expectations aren't met. I can and have been disappointed but I have been fairly thoroughly (thanks to the DISboards and our great posters) educated as to what to expect, and what are real possibilities for disappointment but are still within the realm of reasonable possibility (i.e. getting placed in an HA room when you did not request that). We'll be travelling with twin toddlers and a 6 mo old so that will also add to the potential issues. I appreciate basically all these posts because they essentially remind me that it will be CRITICAL to manage my family's rather high expectations, and plan extremely flexibly. My mother frequently compares things to "Disney World" as the gold standard of customer service, but I don't know if the current reality will hold up to her memories. Additionally, we may all have very different expectations for meals, touring, time spent together/apart, etc. And a DVC villa, while we prefer and love it, is very different than a hotel suite with daily housekeeping and fruit baskets from the management as we experienced 20 years ago.
There are many places to vacation and you may want to ease in with a smaller trip or two later. I know I was thinking about bringing my parents, my sister & her husband, my sister in law and her boyfriend, and my in laws and suddenly realized it was a total recipe for disaster to combine that many vacationers. Especially where everyone would be asking me 'what we do next'... and those that were not asking might be wandering away and missing reservations...
I think I am going to just plan a few key events and have optional event plans daily that people can choose between; some together and some apart.
A lot of your concerns center around misinformation/uninformed CMs. I think I would make a list of the 'misunderstandings' and send an organized email to the WDW inbox so they can correct these issues/educate the relevant areas.