Good question and I am able to answer some of it and make recommendations about what I can't answer. Rohnert Park for the most part is a walkable city. It has a walk score of 51 and has several walking paths within green areas.
Regarding Safety, since I legally can not comment with a yes, no or other I will say this. There are a lot of families living in Rohnert Park as well as college students and professors due to it's proximity to Sonoma State University. I recommend you contact the Rohnert Park Police department regarding crime statistics.
Artisan Sotheby's Int'l Realty