SEO DoFollow Blog Question, Newbie here :)

I'm still very new to this site and I've been learning a little about SEO and Internet Marketing, yet I've come into a little road block in regards to my first practice money making endeavor. It's very niche, and it's a niche that's growing into more competition every month as there is money to be made in the niche, however, there are seemingly *no* dofollow backlinks blogs for that niche at all.

There are forums, there are even a social media community or two, lots of top lists and other ways to build links to get traffic, but as far as raising page rank it's seems almost impossible. I'm a rebel and I don't want to do what everyone else in the niche is doing, so I started by providing valuable content (with more coming), writing an article in an article directory, and joining the most valuable niche communities. But now I want to put my competition into the dust by raising my page rank with commenting on dofollow blogs -- slowly, with care and respectfully.

So here are my questions:

-What to do if there are no dofollow blogs in your niche?
- Will it do me good to comment on dofollow blogs that are in topics of my interests, even if they are NOT in my niche?
- Would it be a good idea or a bad idea to make my blog and site dofollow and market it as the ONLY dofollow blog in my niche to those others whom I find worthy within my niche?
-will it hurt to have my blog be dofollow if I'm getting both inbound links and outbound links? (keeping it balanced)
-The niche is mature and can be considered adult, but it's not directly triple X rated, can I still get back links from .gov and .edu sites or is it much harder?

Sorry for the questions...but I've spent about 5 hours doing very careful online submissions of comments and I'm very thorough. I'm having fun with it too, but I'm worried that I'm doing it all wrong.

Any hints for this newbie would be appreciated....