In most cases a professional is required to fully eliminate a pest problem, DIY solutions can offer a temporary fix but do not solve the underlying cause
This will largely depend on the type of infestation, please consult with an expert for more information
For many indoor treatments, you will have to vacate for some period of time, though not in every circumstance. For outdoor treatments you usually do not have to vacate.
This depends on the nature of the problem and the type of pest. Please consult with an expert for more information.
Preventative care is not required but will dramatically reduce outbreaks and make dealing with any problems much easier