Variable. Anterior shoulder stabilization or bankart surgery is fairly routine but length of surgery is variable depending on extent of labral tearing and which type of approach (arthroscopic vs open) is taken. Sometimes additional unforseen pathology is encountered which can lengthen procedure.
Varies Widely. As with all things the duration and details of the procedure really depend on the level of skill and experience of the surgeon as well as the extent of pathology. You can learn more here: http://theshouldercenter.Com/unstable-shoulder.Htm.