A: Hello. This only applies to the Keyword Planner feature of the app, and nowhere else.
All course searches and their result sets are unlimited. In the main dashboard, the course meta-search engine searches are unlimited. As is filter applications, saving, etc.

I tacked on the Keyword Tool as it is beneficial, but not in heavy use by most generally except for those doing SEO or who are starting to market their content; so instead of raising the price for the entire app I added it as pay-per-use feature with a default to included 120 calls per month. After that, if you need more of that particular research, you can purchase keyword packs in increments very cheaply.