Keyword research questions

I've gone through few keyword research tuts from bhw. But still I have some doubts.

I used Market Samurai to check SEO competition and for eg, in top 10 I find 8 URLs without backlinks (and these two have small amount of backlinks, like 10-30), some of them are fb fan pages, dailymotion/youtube videos and top 3-5 are On-page optimized. But when I check competition using "kw" in google I found around 6,000,000 searches. For inurl:"kw" I get 70k and intitle:"kw" around 170k. And for inurl:"kw" intitle"kw" together I get around 60k.

I'm confused now, cause Market Samurai is telling me that competition is really low almost none but google search results are saying opposite.

Does this means that there are a lot of sites targeting this "kw" but they are not SEO optimized?
How hard will it be to rank for "kw" like this one (consider that I'm total newbie while answering this one. And there is no authority sites in top 10)?

And what means "Majestic index: historical/fresh (last 60 days)" in Market Samurai in SEO competition tab ?

Thanks in advance.

Let me tell you my easy old fashioned method.

1. Find the keyword
2. Check the first page results
3. If there are some strong EMDs, go away...
4. If not, buy domain, fill the content, and promote...

Thank you for suggestion. Still I would like to get straight answers.

I haven't used Market Samurai, but I think the reason there's a difference is either because the metrics are different (1000 on one could be termed 'low' and on another could be considered 'medium'), or that the database is outdated.
We've always been using Google directly for analysis, and unless you're looking at a great number of sites and competitors, keyword research is best done manually using Google External Keyword tool!
My 2 cents.