Not surprising that most people didn't like the movie...
Well I did like it to be honest ^^" I found it a rather fun movie to watch, I bought the DVD and I want the sequel!
No, I actually MEAN it!
Of course they changed almost everything, but I just see it as a more realistic version. That includes sending Goku to school. I mean at least he didn't loose his naive character completely and he got Chichi in the end. Be honest, in present times it would have been reeeeaaaallllllyyyyy unrealistic if Goku didn't know about beeing in love and so on (like the Goku in the Manga/Anime...how did he ever manage to produce 2 children???).
To start the story with Piccolo was a good choice, i think piccolo is the most popular 'enemy'... I also don't like the stories of Gokus childhood...to me it's not that important for the story as such. That he transformed without a tail isn't bad either!
You maybe know that Goku in the manga/anime looses his tail and the ability to transform into the great monkey. In the movie they just made it less complicated. It is after all just a movie, to tell the story behind the tail, and that something like that happened before would have just been a waste of time...
A sequel would be nice, I want to see how they make Piccolo turn into a good person.
In the end I have to say I am happy that you didn't say anything about Goku not being asian (or did I just skip that?) I mean yes, the Manga is japanese but they never mentioned anyone of the Manga to be asian or not. So I'm not mad that Roshi looks different. I thought Chow Yun Fat was a great choice and he would look odd with a beard...