Lisa,
I would move your analysis to a new area. You may want to pick 2 or 3 of the top niche keywords to start with, then ask your self some of these questions...
1. How are you going to make money in this niche? That is why you are here right?
- Selling products, being an affiliate, write ebooks, articles, other?
2. How are you going to get traffic to my website or sales page?
- run ads? blogging? write articles? forums? mailing lists? viral marketing? other?
3. Do you have any interest or experience in any of these niche areas?
- this could help depending on what you plan to do in #1 & #2 above.
4. What are the top sites in that Niche now? What are they doing?
Can you do it better? or can you do something different to stand out?
I would assume that some niches are better for certain products, or approaches. Some may have products you can resell or be an affiliate. Some you may have to create products or services.
There are probably more, but if you start with this, plus your keyword research, you should be able to come up with some pluses and minuses for each niche.
But at some point, you do have to pick. Give your site a fair shot. Whether it makes you tons of money or not, you will have gained valuable experience. That you can now use to evaluate your list for your second and third niches.
Good Luck.