Anxiolytics

What is considered first-line treatment in regard to pharmacotherapy for Generalized Anxiety Disorder? What is second line? (You may need to research this, please cite your source).
Explain the impact half-lives have on agent’s tolerability and efficacy. For this discussion, concentrate on Z-Drugs.
Which benzodiazepines are approved for insomnia? Are the considered first line agents in the treatment of insomnia?