The best way to get an understanding about your new business is to get it out to the people. Launch it! That is the best possible feedback that you can receive. Your co-workers, investors, friends and mom all have thoughts. They don't really know though. The consumer is the ultimate decider.
The constant theorizing, tweaking, testing, thinking and talking all delay LAUNCH. There is need for some of that as your develop the product, but it passes a point where it just gets counterproductive. I think the more academic the people are the more they struggle with this. Let's think of every possible thing and have a plan IF it happens. Overthinking at it's finest.
I read a funny quote that essentially stated that the best entrepreneurs are B students because they aren't smart enough to know how bad their idea is. They just launch it! Some of the ideas end up being great and they achieve success. An A student might have just squeezed the idea to death and never got it to market. Or cut it down so much that it lost it's appeal.
This is obviously a subjective call because every person's business is different. I do think less thinking wins the day though. Let the consumer experience the product and adjust from there. You'll quickly see where the issues you and you fix them. Some of the things you thought would be issues just weren't. Some things you didn't foresee ended up being issues. Great to know!
The startup needs momentum. You need wins (like actually launching). You need feedback. You take the feedback and adjust. That is the consumer feedback loop that will lead to success.
You never enter the loop if you never launch.