Do you need a talent agency license in Kansas to open a modeling agency for just Promotional modeling?

You do need a general business license in order to open a modeling agency, regardless of what type of models you tend to represent. The nature of your business as a modeling agency will come into play when you fill out the appropriate forms. Below is a link to a form for an application for an employment agency license in New York:

http://www.labor.state.ny.us/workerprotection/laborstandards/pdfs/ls355.pdf