Do I really need longtailpro keyword when I have adwords

As an blogger aiming to make extra income online making use of my free time I always check useful tools, plugins, themes and don't hesitate to buy if needed. As such I've bought some premium themes priced at $300 for some of my websites and I'm extremely happy and satisfied about my purchase though I'm yet to recover the money spent
These days many bloggers talk a lot about longtailpro keyword tool. when I read reviews of these bloggers I get a simple quesiton in mind. Should I spend money on this? I own many different niche websites that are doing better but do I really need this to grow my business.
As a matter of fact I read an interesting post on this tool review by a popular professional blogger and here is my opinion on this
1) Keyword Competition Analysis - In my opinion Google Adwords has a feature called Keyword Planner. We can determine the keyword competition like low, medium, high using this tool and it is absolutely free
2) Average visitors for keyword - Keyword planner offers this for free. We can get to know CPC called Cost Per Click on keyword of interest. Note that we cna get to know average monthly visitors on each and every keyword
3) Long tail keywords - In simple terms they are related keyword. Say the keyword is blogging then long tail keywords can be blogging for money, blogging for marketing, professional blogging and all related terms. This is visible in keyword planner and I see no reason to buy this tool
4) Domain authority, Page Authority, Backlink PRofile - There are umpteen number of online websites that offer this for free
5) Ranking in different search Engines - There are free tools that does pull information on how well your apge ranks in different search engines. You have option to signup in webmaster account related to different search engines like google, bing that comes absolutely free. They pull traffic and will let you get details on queries, where does your website land for these search terms etc
We can stick to free tools instead of pouring money on tools that are marketed for affiliate commissions. We can help you with your media marketing