Additional costnot included will be the incurred costs of city inspections, permits andunforeseen code additions""Any change orders will be authorized before work is performedAdditional Bill for Permits, Engineering and Code supplement will bepayable upon approval and payment (documentation provided)."

I don't have first hand experience with STRs, but from my experience hiring Remote Assistants directly I think that sounds like a decent rate if they provide the advertised services at a high level.

Man, I'll take 18% CoC anywhere I can get it, provided the deal fundamentals are solid. 

I am currently seeking recommendations for insurance agents or companies that can provide coverage for my property.

I am good for a credit check and can provide the lease proving $1250/m income. 

Though, keep in mind that HELOC rates can fluctuate with the market, potentially exposing you to higher interest rates down the line.On the other hand, a cash-out refinance could lock in a fixed rate, providing stability/predictability in your monthly payments.

Before making any decisions, review the information provided by San Francisco's Office of Short-Term Rentals website, consult with local experts such as real estate agents or property management companies that specialize in STR.

In order to provide this outperform service for STR, how many units can you most have to justify your time/effort?

C+ Neighbourhood13 Unit Apartment Building (Link: https://www.loopnet.com/Listing/7828-S-Essex-Ave-Chicago-IL/30374409/) The average Rent is $1400-1500 (to be safe $1300, but I am extremely confident that I will be able to rent higher adding value and convenience to the tenants and treating them as a bit with a higher level of service) - $16,900 at full occupancy and ~$12,000 at 70% building. 

This data is readily available and usually provided by larger brokers.