The NUMMI factory is designed for an output of 300000 cars per year. And thats the number for a GM and Toyota venture producing very complex gasoline cars, not Tesla using robots to produce relatively simple electric cars.
I'm pretty smart finance folks have learned from GOOG stock structuring and the like to prevent LBOs/corporate takeover threats. I'm reasonably sure some of them work for Tesla.
Why would you assume it would be hostile? Ultimately either someone's going to buy Tesla, or Tesla's going to buy a legacy automaker that's in trouble. Setting aside dealership issues in the US, it doesn't make sense to rebuild an entire worldwide distribution system from scratch when the innovation is the car, primarily. Either that, or license the Tesla tech to a major car manufacturer and let them serve the downmarket while protecting the Tesla brand as high-end and innovative. I don't think Tesla wants to become Honda.
Being acquired would definately be a hindrance with the goal of bringing an affordable EV to the masses. I don't think it's about the money from there on.
I wonder if that "expertise" could be more negative than positive. As with software there is certainly a good deal of benefit to having a fresh company, without legacy baggage.