I really admire you for deciding to focus purely on songwriting, its a bold step but im sure your brain will thank you for being able to focus rather than have the distraction of engineering if you feel its what you want to do!
I am regularly changing the "hat" i wear from teaching, gigging, recording drums and also writing material. I quite enjoy the fact it always keeps things fresh but it can be hard to really separate them allowing me to really focus on what will benefit me most at the time.
Hope it works out well for you
Ryan