FYI, I do not make the laws that govern the state of California. In your question, you asked how much to charge "your" shop. If you are an employee, you do not work that way. You are to be paid hourly and the employer is required to follow all the laws set forth by the state of California. What you and your shop are doing is illegal and the business owners of that "shop" know it. They are trying to save money by declaring you a "subcontractor" so they don't have to pay worker's comp insurance or FICA taxes plus they can hold you responsible for the work. But to be a subcontractor in California, you must hold a license for the classification you are working in. And you don't. It isn't about being "friendly", it is about being legal. Why should I help someone break the law? If you read my many posts, I have helped more DIYers and other pros than almost anyone else here on this board. But I draw the line at illegal activity, especially in my home state. I suggest you talk with an employment attorney or check out the state labor laws and see for yourself. I've been doing this for over 25 years and have hired employees, paid taxes, insurance, run my own business, and contracted to numerous customers. I think I am fairly qualified to judge the situation correctly. You can only "work under your employer's license" IF you are an employee. And if you are an employee, you do not tell your employer how much you are going to be paid to do a project. It doesn't work that way. Ask your shop if they are paying their share of FICA taxes for you, if they are paying for worker's compensation insurance for you, if they are with holding state, local and federal taxes as required by law, if they paying state and federal unemployment taxes as required by law, if they are with holding state disability insurance payments as required by law. If the answer is no to any of those questions, then what you and your "shop" are doing is illegal.
Sorry you think that is unfriendly.