I'll give it a go.
1. Nope, new to this forum, and I couldn't care less.
2. This is obviously True for good reason.
3. It won't kill the product, so no. It may be exclusive, which gives more value, but it won't die because it is still the best home automation platform available.
4. Sure, I'll agree to that, but as the answer above, it's exclusive and for good reason. Sales might go up, but there will be a huge amount of people that wouldn't know how to configure it. Composer HE exists and is the solution for the homeowner. Same with When/Then.
5.No, lol, and that is silly to think. Composer HE is fine, but there are things in Composer Pro I would not want any customer using and opening it up would make the dealer certification pointless.
Could HE have more features? Sure, that can be debated. Probably the more appropriate way to ask about more access.