Although I think this is an open question, I don't think that the "subspecies" comment means anything incriminating. As an above poster mentioned, "You can't help but feel that the Chinese are a subspecies" is very different to saying "The Chinese are a subspecies." I'm absolutely not a Morrissey apologist, but I'm surprised at how much controversy that simple comment generated.
Regarding the matter at hand, I actually think it's very likely that, had I not been a Morrissey fan already, if I heard all of these accusations and then listened to the lyrics of 'Bengali in Platforms', I'd probably think that Morrissey is racist. However, knowing what I do about Morrissey and his music, I think that 'Bengali' is an interesting take on being an outsider (and, in my opinion, an under-appreciated classic!). 'Bengali' is the only one of the so-called "possibly racist" Morrissey songs that I can see anything questionable about in the lyrics (though I don't think he means it to be racist, even if his views are that way inclined). I can't see anything remotely "racist" in any of the others that get mentioned. I mean, really, how can anybody who's actually listened to 'National Front Disco' and 'Asian Rut' possibly see anything racist in those lyrics?