(1) Is there an employee requisition system?
Not necessary, but a good idea for expense control and other reasons (see question #2).
(2) Does the requisition define essential functions and take into consideration the mandates of the ADA?
It should to protect against a claim of discrimination. You must outline the duties, especially if they are exclusionary to the disabled or any other protected class.
(3) Are tests part of the hiring process?
(4) Are the tests validated?
If a test is used, it should be validated. Validation means that it is a quantified predictor of success on the job and that it is not exclusionary because of race, sex, etc. ...