While I definitely agree with most of your points raised in the first post and the overall difficulty level in general, there are some points that I don't think people clearly see from Nintendo in general with regard to how Galaxy is structured.
First off (paragraph about Nintendo in general), with the influx of all these new "soccer mom"/elderly/kid/women type of people playing the wii after being on such a huge gaming hiatus/never in their life, people like Miyamoto/other developers of Galaxy could not under any circumstance risk or afford to make the game horribly difficult or "hardcore" just to appeal to the hardcore fans, especially with a game with Mario tied to it.
Iwata himself said that Nintendo's "plan" with Wii/DS was to cater to the new people, and then after an unspecified amount of time, somehow start luring them into the regular core games... Galaxy is/was THE game to achieve or start that, if at all planned (Brawl edges it out in sales but that's honestly in the hardcore-only class). Another example of that is common complaints you hear from people and the Wii's storage solution problems and Virtual Console/WiiWare downloads (fridge jokes). I really don't think they want/wanted to introduce anything that would have the word "Gigabyte" attached to Wii (maybe at E3 :P) since that would, in their eyes, not be appealing to the new crowd that's likely making the system sell out every month. And truth be told, the people running out of space truly are a small percentage of users, I'm pretty sure there's tons of consoles with only 2-3 casual games taking up a save file.
With that in mind, some examples people raised in this thread about how you only need half of the total stars in the game to win, or how some stars are undeniably mind-blowing to get are legitimate reasons in how the extra difficulty is there for people who want it. If you're a 100% completionist, that's wonderful, some of the stars took many lives of mine to be honest. Most people took the 3 bar life meter to be an increase in difficulty, not some crazy confession of how childishly easy the game is they gladly scaled the game down from the previous Mario games.
If people in general are complaining about trivial things such as that one toad who gives you a 5-1up gift from Peach/Toadstool right at the beginning, that's seriously for the people who are less gifted than the typical gamer :P No need to accept it if you don't want to. I agree that the map/hub overworld in Galaxy felt pretty straightforward versus 64/sunshine, though, yet again Nintendo couldn't dare alienate people so early in the game with a different design choice right?
As far as the poll is concerned, 9/10 is probably my overall enjoyment rating of the game as a whole. I unfortunately found myself slaving over the last 10-15 stars just to see the special "stuff". Games like Radiant Dawn have accumulated many more hours, and gladly so :P