As a quilter turned designer I still don't have a huge fabric stash or tons of rulers. For fabrics, I buy what I need for a project... no more no less. If I do have some leftovers I try to use them within the next couple projects. As for thread, I keep gray and off-white for piece work. On rare occasion will I use another color. Your fabrics will either be dark, medium or light. Gray blends with medium to dark colors, and off white blends with medium to light.
You can do a ton of cutting with nothing more than a 6" and 24" square rules. Trust me. I did so for many years and my quilts still came out just a good as they do with specialty rulers. In fact, many times I go back to my old faithfuls. The most minimal method is using templates for everything... even squares. Not so many years ago, that is how it all was done.
A good rotary cutter is ideal but along with it comes a cutting mat 18" or the size of your longest ruler. Yet there is always the option of just using scissors.
Being a minimalist is great. It prevents storage issues and keeps the cost of quilting down!
Oh, and honestly, you only need one sewing machine.
Just for fun...the pictures of templates were my grandmothers.