Additionally on (A) this is massively beneficial to contractors. They cannot force you to work in an office or the hours you work which is key for a freelancer/contractor/creator/developer.
The items are already part of California's contract law well before this current gig economy bill.
California classifies 'independent contractor' as [1]:
1. Whether the person performing services is engaged in an occupation or business distinct from that of the principal;
2. Whether or not the work is a part of the regular business of the principal or alleged employer;
3. Whether the principal or the worker supplies the instrumentalities, tools, and the place for the person doing the work;
4. The alleged employee's investment in the equipment or materials required by his or her task or his or her employment of helpers;
5. Whether the service rendered requires a special skill;
6. The kind of occupation, with reference to whether, in the locality, the work is usually done under the direction of the principal or by a specialist without supervision;
7. The alleged employee's opportunity for profit or loss depending on his or her managerial skill;
8. The length of time for which the services are to be performed;
9. The degree of permanence of the working relationship;
10. The method of payment, whether by time or by the job; and
11. Whether or not the parties believe they are creating an employer-employee relationship may have some bearing on the question, but is not determinative since this is a question of law based on objective tests.
The key line for software developers who are independent contractors is "Whether the principal or the worker supplies the instrumentalities, tools, and the place for the person doing the work;"
Contractors that work in a home office, using their skills to bring to a company for a project, at their own place, time and tools, that is an independent contractor.
It could be argued that drivers that own their cars, that can choose to accept or deny a particular task, without it hurting their competitive rating, could be seen as an 'independent contractor'.
I think the gig economy bill from OP is targeting known companies that are taking advantage of this by wanting 'independent contractors' that they can schedule and dictate their day and use metrics against them when they aren't available at the time. They should pay people as employees if they need people available then have contractors fill in when needed. This will probably lead to some fulltime Uber/Lyft and the rest floaters that can be like the current gig setup.
[1] https://www.dir.ca.gov/dlse/FAQ_IndependentContractor.htm