Yes. In order to run any legitimate business that is for profit, you must have a business license.
Yes. You need to have the proper business licenses according to the state you live in so that you can own and operate a modeling and talent agency.
talent
Yes. Each state has its own requirements so you can check out this URL to a site called the Association of Talent Agents: http://www.agentassociation.com/frontdoor/agency_licensing.cfm
Yes, a model is considered a "performing artist" and the laws governing talent agencies in Florida revolve around protecting "performing artists".
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
no you just need to have actual talent
You need to contact a talent agency in your area.
No
This will depend on what state you live in. Each state has its own requirements. Check out this link, which offers information on license requirements for talent agencies arranged by state: http://www.agentassociation.com/frontdoor/agency_licensing_detail.cfm?id=571
No. You need special training and a professional license to be an orthodontist.
no
Based on searches online, there is no "Seattle Talent Agency." If you are asking about how much it costs to join any talent agency in Seattle, the short answer is that legitimate talent agencies are not allowed to charge any upfront fees. So it should be essentially free to sign with an agency. Later on you may need to pay for acting classes as well as any photoshoots you need to do, unless your agent allows you to do free test shoots with photographers.