Regarding Number 2: You employer DOES have to pay you the difference. If your employer is telling you differently, I suggest you contact the Department of Labor. While some states do have minimums that are different that the federal, an employer should honor the one that is higher: The Fair Labor Standards Act (FLSA) requires payment of at least the federal minimum wage to covered, nonexempt employees. An employer of a tipped employee is only required to pay $2.13 an hour in direct wages if that amount plus the tips received equals at least the federal minimum wage, the employee retains all tips and the employee customarily and regularly receives more than $30 a month in tips. If an employee’s tips combined with the employer’s direct wages of at least $2.13 an hour do not equal the federal minimum hourly wage, the employer must make up the difference.
Some states have minimum wage laws specific to tipped employees. When an employee is subject to both the federal and state wage laws, the employee is entitled to the provisions which provides the greater benefits. That is copy/pasted directly from the Department of Labor website.