[plugin: GD star rating] SIMPLE instructions or tutorial

I have spent ages going through the options and docs for this plugin and am completely and utterly confused.
I have eventually managed to get a star rating displayed at the bottom of the post, which is populated by the ratings given in comments – a basic ‘visitor reviews’ setup.
I have set category control to articles:hidden for all my current categories, as i only want to show these settings for a new ‘product review’ section i am adding to my site.
However it has still added it to ALL my posts. I can change them manually by going into edit post and setting the display to ‘inherit from category’ but i cant do that for all 2000 or so old posts!
Is there any way to remove it from all my old posts?

Also, if anyone can help, is there any way to add a multiblock (i think thats what i mean!) instead of the single line of stars in the same way i have set up.
Eg visitors can vote on a range of aspects? I have created a multiblock with 3 options but cant seem to get it integrated with the comments.

Overall this seems like a massively powerful plugin but its got so many options i cant work it out.

thanks