Obi, whilst I agree with you on the majority of your points, I still feel that there is a certain degree of subjectivity involved when it comes to the problem of working out intentionality. For instance:
We should fix Dream Eater so it works on Substitutes. All of the other draining moves do.
I would say that this makes sense for the following reason. The mechanics of Dream Eater dictate that a check on the status of the target is made before deciding whether damage is done or not. If the target is asleep, the move goes through. If not, it doesn't. Since Substitute is always the target of an attack while it is up, and Substitutes never have the Sleep status by definition, it surely makes sense that the attack would fail.
Substitute should block the effects of Static, Poison Point, etc. It makes no sense at all (and obviously goes against the status-blocking wishes of Game Freak for Substitute) that Substitute doesn't block being put to sleep by Effect Spore.
I'm not sure about this one either. The reason being similar in that the 'target' of pseudo-status traits is not the Substitute, but the object that made contact with the Pokemon having said ability.
Reflect / Light Screen should not be broken when Brick Break hits a Ghost. Ghosts block Rapid Spin, so why should they not block this? Must be an oversight by Game Freak; I'm sure they'll fix it in the English release of Platinum, as long as they're aware of it.
Pardon my ignorance here, but I have a question. What was the case back in ADV? If Brick Break's secondary effect was blocked by Ghosts back in ADV but has been changed in the transition, then I might
possibly agree with you, but I'd still have my doubts. If it wasn't, then I'd say that this was intentional.
Of course the most intuitive solution would be that both moves activate their secondary effect regardless of whether the move hits a target or not. After all, the objects they are removing are entirely separate from the Pokemon themselves. Then again the same could be said about Substitutes and Evasion, so it is obvious that Gamefreak's intentions do not conform to intuition.
I feel that the fact that we disagree on these points goes to show that there is some degree of uncertainty in trying to determine Gamefreak's real intentions, which is one argument against the idea of implementing game mechanics via this philosophy. At least when it comes to simulating the game literally you can be 100% sure that you're doing it right. Just my 2 cents.