Is a job offer from a US company a requirement?

In general, you cannot apply for a US work visa without a specific job offer from the US. Additionally, the application is handled by the US employer and not by the foreign employee. An application independent of the US company that is acting as employer is thus not possible. Usually, two branches of the company are involved with the L-1 application process – the foreign employer and the US office. The company acts as the petitioner, the employee as the beneficiary.