After seeing and hearing is a few times I do agree with you on those points. I still like it, but yeah it probably would have been better as an ending theme. Openings should be stronger probably; this one has a weaker singer as you said and kind of whimsical animation almost that doesn't really stick in your mind.I didn't really like the opening theme. The singer has a weak voice, and I thought the random parts of them running through random blobs of colours was rather lazy animation - that sort of thing is usually left for the ending themes. I thought it was just a bit childish really, and I mean by Pokemon standards, ha.
The random trainer looks a bit creepy, like a younger Conway, hahaha.