If you're going back and forth everyday, I would ignore every suggestion to stay outside SF, except for maybe stays in the Daly City-adjacent areas since more trains run through there. I travel to the Bay Area on occasion for work (and used to live there for a few years), the travel time + BART costs wouldn't be worth it IMO.

In terms of "Hacker houses", I've only known one person (a coworker) who stayed in one long-term, but he was pretty eccentric. He complained about his living situation a good amount, but, attempting to reduce some of his biases, they seem to be in a "you pay for what you get" type of situation.

Last suggestion: book an initial stay through a hotel/Airbnb with a short duration -- with the intent of finding a co-living space if you're really that intent on living in one. This will give you time to scope locations out _in person_ and potentially toss out options that only look good in advertisements.