How do I add housemates as a Master Tenant in San Francisco?

[Britt Mauriss]

I've got a bit of unusual situation here and am wondering if any folks (perhaps attorneys?) in SF have some insight.....

On 9/1, I leased a three-bedroom apartment in San Francisco from the landlord who lives in the upper unit (owner-occupied duplex). I didn't know who I was going to room with yet and wanted the flexibility to screen and choose my own housemates, so I took on the lease myself as Master Tenant. Now that I've got someone to screen, the landlord's process is to submit their rental application to a third-party screening service (applicant pays me the $30 fee to pass onto them), and if they're approved, the landlord informally OKs it without signing a lease or accepting rent payments from the new tenants. This is legal under Costa Hawkins and I'm comfortable taking on the lease individually, but am not sure how to explain the situation to new housemates. Many people prefer the security of a one-year lease in SF, particularly for rent control and eviction protection. My lease with the landlord strictly forbids subletting, so I'm not able to draw up a sub-lease agreement with the new tenants. As far as I know, they won't be on a lease.

My main questions are:

- What if they ask to be on a lease? Is there a type of agreement I can create between us that does not constitute subletting?
- How do I handle security deposits? What if they ask for a receipt or something stating that they paid me a deposit? Should I create my own receipt to give them? 

I feel shady asking people to agree to an odd situation like this - or is it not that uncommon? First time I'm navigating this so I'd love any guidance you can provide.