In reality God chose the fruit of a tree to test mankind (of course there were just Adam and Eve at the time). However, it could have been anything ... it could have been a BIG red button they were not supposed to push.
The point is this ... God wants us to obey Him because WE CHOOSE to -- not because He has given us no other choice as you have suggested by just not having the tree there in the first place.
It is good that you have looked into at least one of the world religions (Buddhism). However, I suggest that you search out the others as well -- not at a superficial level but really look into their differences. Of course I believe with research & logic, the only viable religion is Christianity. Not your run-of-the-mill "Christianity" but the one prophesied in the Old Testament and fulfilled and defined in the New Testament.
Think about it. Research and study it. Figure it out.