As for the history of the company, as I explained, I created Long Tail Pro back in 2011.  At the time, I was creating tons of niche sites and was doing alot of keyword research and content creation.  I was trying to figure out what types of keywords would rank quickly in the search engines, specifically Google, and I was frustrated with the other keyword research tools (in particular Market Samurai) out there.
3. Set your pre-search filters. Depending on whether you are looking for a new niche to build a site around or trying to find keywords to target on your already existing website, the minimum amount of local monthly searches (LMS) you set might vary. For new niches my LMS criteria is 1,500-5,000 searches, for posts anything from 10-800 is fine. Also, depending on one of these goals you can add a lower or higher number of words in the respective filter: for new niches 3 (or, at times, 2) words minimum, for new posts from 3 or 4 words up.
I think people's aresenal of keyword research tools are mostly the same: 1) You need a tool to examine search volume, most likely Google Keyword Planner 2) A tool to help you generate more keyword ideas. Tools that work with the search engines' autosuggestions are very popular such as and Ubersuggest 3) Then people might add a tool broaden the depth of their data, maybe including something like Google Trends or Moz's Keyword Difficulty tool.

The limit on manual keywords could be higher.  I personally wish we could input 10,000 keywords at a time, instead of 200.  However, I understand the costs that Long Tail Pro has to maintain each time a new manual keyword is input.  Not a deal breaker, I just wish the limit was higher. (To be fair, I don't think most keyword tools have a bulk manual option at all).