Writer. Director. Welder. Shooter. Carpenter. Editor. Father. Fool.
Ok, can we all admit that self-doubt as a writer (or any other art form for that matter) has absolutely zero to do with what software we are using? Software that works for your specific writing style empowers you to write when you know what to write and have some degree of confidence in writing it. There are many roads through the self-doubt phase of the process, but I've never seen a specific software that was the breaking point for pushing through that. All that being said, if the method of this software helps some writers be more productive, then I'm sure it's well worth the price.
I think it's all great advice. Some of the statements are less important than others.
The best advice I ever found on writing was in Stephen King's book of the same title. One of the best books about writing ever penned.
All that being said, "never say die" can't be repeated often enough either. :)