Can you and 2 of your roommates grow together in one location? = Yes
Do caregivers have to grow at thier physical address? = No
Can you lease space to create a collective garden? = Yes

I would try to stay under 100 plants per location even though Obama has said that they will not be stressing people that are following state law. I would also label which plants are yours in whatever shared type of grow that you do.

If you have any more questions let me know,
Feijao