My goal is to have vacant possession at closing or as soon as reasonably possible after, without putting pressure on the tenant or making the seller’s life difficult.For those who’ve been in similar situations, what’s the best way to structure this in the offer so it’s fair for everyone (seller, tenant, and myself)?

From the Tenant Buyer I get an Option Payment of $25,000 and a rent payment when they take possession.

In CA, “exclusive possession” is a term to understand.  

If you don't, you need to find a local eviction attorney ASAP (and then perhaps find a property manager after you get possession of the unit). 

They usually grant 10 days for payment, on the 11th day you file possession - then another 10 days and locks are changed. 

@Isadore Swartz I know they left early they turned over the keys when they were transferred so I had possession.   

The property isn’t guaranteed vacant, so you may need to handle post-sale possession if occupied.

- Does the seller need post-close possession?

By chance do you possess formal education in business analytics?  

We can absolutely use more knowledgable agents who specialize in helping investors.