If I create a good community in my particular field on my SEO site and have a quality Q&A section like this etc (ripping of MOZ's idea here sorry, I hope it's ok) will the long term returns be worth the effort of creating and man ageing this. Is the user created content of as much use as I think it will be?

I'm thinking of using rel=canonical for similar products on my site. Say I'm selling pens and they are al very similar. I.e. a big pen in blue, a pack of 5 blue bic pens, a pack of 10, 50, 100 etc. should I rel=canonical them all to the best seller as its almost impossible to make the pages unique. (I realise the best I realise these should be attributes and not products but I'm sure you get my point) It seems sensible to have one master canonical page for bic pens on a site that has a great description video content and good images plus linked articles etc rather than loads of duplicate looking pages. love to hear thoughts from the Moz community.

I'm finding it hard to build quality links. I don't want to employ a link building company as I can't find anyone I can trust. I also don't know what is a realistic rate of pay for link building work.

I have done a manual link audit and made a good, bad and not sure list. Is there any tools I can run over the list to see if I missed anything and help me decide what to do with the not sure list?