MartynRich - Thanks for the advice, Martyn. I always appreciate you taking the time to comment like that. I agree, there are certain parts that drag on and the tempo-change is a bit unnecessary. To be perfectly honest most of the time I'm unaware I'm doing it. I'm still developing and trying to find new routes and avenues to explore, and it certainly helps being a member of this forum.
Tinam - I just gave both of those artists a listen and I can see what you mean. I'm naturally not capable of a really brilliant voice like Sam Cooke or Freddie Mercury or something, so I take my lead from artists like Lou Reed etc who made a very unmusical voice into something that worked within the contexts of his own songs. I'm glad that you liked it!
I'm working on a couple of songs now that are a bit sung a bit more conventionally, so after working on those I may return to this. I think all it needs is another vocal take on some parts of the verses and, like Martyn said, a more sustainable tempo.