I agree with the point that this discussion in itself is proof that pitch is not necessary for a beginner. If you do a search for academic papers on pitch in Japanese languages, whilst there is consensus that it exists, there is a wide range of opinions on its form and classification. I seen an article that claims it should be classed as an impoverished tonal language, and an other that says that it is closely related to stress in English. Well, it can't be both.
In the article I linked to, it gives similar examples where perception in English differs from reality. E.g. the difference between 'chi' (Greek letter) and 'guy' is actually aspiration rather than voicing. If a foreigner tried to improve their pronunciation by following a native speaker's perception then they will actually end up sounding very strange indeed.
I finished a Japanese pronunciation course a while ago, and I really wanted to continue but time and money didn't allow. Anyway, the main gist of having correct Japanese intonation was as follows:
* Individual words have a set pitch pattern
* This pattern is not used when the word is part of a sentence in normal speech
* Words do still differ, but by the rate at which the pitch falls, rather than rising and falling
* The difference in fall rate is not necessarily related to the pitch pattern in the isolated word
There was quite a bit more to it that that, though. The teacher was really good.
If you're interested, this was the place:http://www.nihongo-hatsuon.jp/