avidnote

I know the exact situation that you are in. I was thinking the same, I ended up finishing my PhD this summer. My dream was to be able to drop out of school at some point to pursue my startup but my PhD took so much time, I ended up never committing to my idea fully. Now that I'm finished, I've decided to take a paus from full-time academia and instead try to bootstrap my startup idea. Have you thought about bootstrapping it? Funds from friends and family?

In my experience, research journals typically have a clause that your paper is not currently under review for another journal. Be sure to read through their terms of service, it should be stated there. If not, it's usually included when you're submitting your draft.

You don't need a PhD to publish a book. Obviously it lends you some credibility if you do have a PhD in the field that you are writing about; but there are also many cases of great science related books that have been written by individuals who don't have a PhD. May I ask, what your area is?

Taking a walk in the woods is definitely underappreciated. It's a great way to refresh your mind and get some inspiration.