The most important thing to think about first is making your site user friendly/ understandable before worrying about seo. If your site's main objective is to make sales then your content should reflect that first, then you can integrate your SEO strategy. (i viewed a few websites which looked crap because they had put the keywords in every other sentence which just did not flow at all, which consequently would lead to potential customers bouncing off the site. (Searches can penalize for keyword stuffing too . . . . I think??) I was told by another expert that optimizing for 2-5 keywords on any given page would be best. The strategy i have come up with is as follows: Link building (reciprocal links are fine if they are relevant and may benefit your users), never use these link building services where they say they will get you 000's of links for next to nothing as Google will penalize you for these poor quality links and ranking will drop. Unique, Relevant content. Search engines love new updated content and will visit your site on a regular basis, thus more pages will be indexed, which may lead to increased traffic. Also gives you a chance to include your keywords into these articles. Submit articles to article sites this is another good way of 1) getting your name out there 2) including one way links back to your site if possible 3) providing good info about what you do 4) adding your keywords in the articles. Anchor text The text of the actual link is important too. e.g. if you sell sports gear, put the keyword "sport" in the link text as searches take this into account too. i am no expert whatsoever, however using this strategy i have seen positive affects on my websites. Experts feel free to examine my approach....
You have good plan. Just replying on articles may make it very difficult for you to raise the number of backlinks. There are many other legit techniques you could use alongside the articles.
Original content is the most important part. When you have good content people will love to link o your articles, etc.
"reciprocal links are fine if they are relevant" I only build one way links. Reciprocal links don't help much. Also, I guess Google don't like reciprocal linking too.