Sorry, but pretty much all of this is not true. AEC installs just fine on all of the Joomla 1.6 installs we have tested, which of course includes non-vanilla deployments. (I'm really not sure how you imagine that AEC is the only component in Joomla to require a system from scratch.) The only scenario I can come up with here is that the servers you tried it one were different - maybe your "plain" test was on a local server and the ones you deployed it on before were servers that had a number of restrictions? Did you test with the latest version that ironed out a couple of minor bugs?
Now, I cannot make out what ticket you are referring to as I don't find anybody with a username like yours in our system, but I'm certain our support did not tell you that AEC only works on a vanilla Joomla. I'm even more certain that Jake tried his best to help you on your path, but maybe you were too frustrated to follow up with us. Feel free to email me directly if you want to discuss this in more detail.
As for the matters of support - yes, our smallest "starter" membership comes with 15 minutes of support time that you can spend on hands-on support. Apart from the fact that you are mocking something that you yourself decided to buy, 15 minutes is actually what we have found to be sufficient to get most people on their way. Then, of course, there is the manual, video tutorials, FAQs and so forth that can also help you along. So yes - the direct, hands-on support is kind of rationed. But saying that "if you need any help whatsoever, you need to pay extra for support" is just false.
Next up - I have a hard time figuring out what your real issues were. Apart from your installing trouble in 1.6, you write things like "There's nothing in the settings that will make it work with anything." - How about the "Integrate Registration" setting that does just that, with the Joomla registration (and JomSocial, CB and a bunch of others)? What about the 50+ MicroIntegrations that specifically target other components?
Finally, there is no need whatsoever to "hack" anything in Joomla to make it work with AEC. We do have a file hacker, but that is a remainder from Joomla 1.0 days and largely unused (it's only there to support some legacy integrations with other components that we cannot integrate with unless we modify their code - something we of course try to avoid at all cost).
I must conclude that what you were experiencing really does seem like a bad dream. Do you really think that we have stayed in business for more than four years now, servicing all those clients on thousands of sites, all while selling a software package that does not work?
Selling it, actually, using the very same software that you claim to be so broken to be unusable?