I currently work as a production manager at an advertising agency, and I will soon be a 25% partner of the firm.

The lenders are correct though, you will not find an agency or government loans with that property.

When one finds a seller and does not yet have a buyer, who does the "agency relationship" go with?

https://www.baltimorecountymd.gov/Agencies/permits/rentalregistration/ Good luck! 

I'm a CA agent, I should probably add an Agency Disclosure clause in the contract right?

Just to give you an example what you'd learn:  Licensing Laws/Contracts/Financing/Principle of Agency/Property Condition & Disclosures/Real Estate Calculations/Practice of Real Estate/Property Ownership/Land Use Controls & Regulations/Valuation & Market Analysis/RESPA/Fair Housing Rules. 

Overall as an appraiser you can sell your services and make decent money that way working for different banks and government agencies.

Any of those government agencies run at their own pace.

@Susan Knight  I spent 15 years doing research and strategy work inside ad agencies and then tech startups.  

(c) The Federal National Mortgage Association; the Federal Home Loan Mortgage Corporation; any agency of the Federal Government; any state, county, or municipal government; or any quasi-governmental agency that acts in such capacity under the specific authority of the laws of any state or the United States.