It can take anywhere from 12 to 18 months without any issues or even longer if issues arise during the process. It is a lengthy process but you have a level of protection the moment your trademark application is on file with the USPTO. 

The registered trademark can last indefinitely if the owner continues to use the mark o or in connection with the goods and services listed in registration, provided that the owner timely files all necessary maintenance documentation. Maintenance documents are required to be filed, and fee paid, before the end of the sixth year, and before the end of the subsequent ten year intervals, following registration.

An office action is an official letter sent by the USPTO. In it, an examining attorney lists any legal problems with your trademark, as well as with the application itself. All legal problems in the office action must be resolved before the trademark can be registered. 

A trademark is the brand name that distinguishes the goods or products of a particular entity from another business goods or services. A service mark, on the other hand, is essentially the same thing, but instead of representing a specific good or product, it represents a particular service offered by a company or other source. 

The flat rate you are paying includes the filing fees that go to the United States Patent and Trademark Office also includes a 15 minute Discovery Call or Onboarding Call, Preliminary Knockout Search, Opinion Letter, One on One Consult, Filing of Trademark Application, and Status updates of application throughout process. This rate is for one trademark, one application, under one class

You can trademark a Name, Logo, Slogan, or Sound

No but the applicant citizenship must be included in the application. If the applicant has dual citizenship, he or she must choose which citizenship will be printed in the Official Gazette and on the Certificate of Registration. 

Yes, a trademark is assignable under certain conditions. Written assignments may be recorded with the USPTO. There is a fee associated with this request.