Guess I need to de-lurk now.
I think this is a grand idea, but... It might be a real challenge to make it work. The Bay Area is flush with options for hackerspaces/makerspaces. However, I don't frequent any of them and the reasons are the ones you'll have to solve.
I live 2 blocks from noisebridge. I basically never go. As a hackerspace done by cryptoanarchists there's no fee, loads of crazy equipment, and everything I've ever tried to use has been broken. I've met a ton of cool people, which is awesome, but I can't really use the space for anything. The sudo room is supposed to be better, but even more computer related. Even further is any of the coderdojos.
There are multiple TechShops, including one about 6 blocks from my house. I don't belong to these either. At over $1K per year plus needing to pay for SBU classes before you can use each piece of equipment, it's just too expensive for how often I would use it. Same thing with the sawdust shop down in the South Bay.
I've found that it's often *not* worth it to do it myself. Acrylic laser cutting is $90 an hour at pagoda arts and that means I can just hand over files and materials and not have to guess about power, speed, and fight with Corel, which is what TechShop requires. There are multiple cnc routing shops in the area and I'm talking to for my next project where they are providing expertise so I don't have to run through tons of material screwing up.
So, all of that is to say... my interest is high, but it would have to fit in the box of: not too expensive (maybe around $50 a month?), stuff that works, good access hours, and enough equipment--and you have the constraints of space costs, liability insurance, and how to manage the space, people, and equipment. I'm pulling for you, and am willing to help a bit, but it's going to be tough.