What's the Best Strategy for Using a Blog to Rank High Organically?

Currently I only have a squeeze page up at domain-name.com and I have been driving all my traffic through PPC - Google, Yahoo, Bing. After seeing which keywords actually convert, I am about to build a long-term SEO strategy around them by setting up a blog.

Would you create a mini-site blog with 5-7 high quality videos/articles and use it strictly as a funnel to get the opt-in and lead them to a members blog that's setup product launch formula style.

OR, would you build an authority site that has those same 5-7 high quality posts/videos but also has more posts and sections for affiliate product reviews, guest bloggers, and something that generates more of a community feel.

I feel like ranking an authority blog that builds a community would provide them with too much content to help them solve their problem and distract them from the ultimate goal, which is to opt-in to my sales sequence and buy my product.

Also, as far as setting up a blog to rank goes, should I use my-current-domain-name.com/blog or should I go back and change the url my ads redirect to and have my blog be my-current-domain////com?

Or do I abandon the current domain I've been using to send all my PPC traffic to all together and build a blog on a new site with a domain name that is an exact match with the best converting keywords I've found from my PPC efforts?

Example: let's say best converting keyword from my PPC has been "how to get over a relationship" and the domain I've been sending them to is getoverrelationship/com

Let's say I also have a domain name that is howtogetoverarelationship/com or how-to-get-over-a-relationship/com

Would it be better to a build a blog around the exact keyword match or would it be better to go with the one that doesn't have the entire keyword phrase in the domain but has had existing traffic (not much, only 2,300 visitors total)

I know Yahoo loves exact keywords in the domain and it helps you rank but I'm not sure about Google. Would the benefit of having the exact keyword match in the domain outweigh the drawback of starting up on a completely new domain that was just registered a week ago?

Your advice would be greatly appreciated!