Yes. It may be illegal to discriminate, but there is no mandate to pay all workers the same wage.
There could be various reasons why you received two different amounts from the same employer. It could be due to overtime hours worked, bonuses, different pay rates for different tasks, or deductions such as taxes or benefits. It's important to review your pay stubs or speak with your employer to understand the specific reasons for the discrepancy.
Yes, you can file your taxes with 2 W-2s from the same employer if you had multiple jobs or positions with different pay rates or tax withholdings.
no
no, "base pay" is a set amount prescribed by the employer.
Sick pay is unregulated. It is a gift from some employers, and the rules are whatever the employer says.
Yes, an employer can pay more for seniority.
No, it is illegal for your employer to require you to work without pay. All hours worked must be compensated according to labor laws.
If you live and work in the U.S. then you are liable for the same taxes as anyone else. Your employer will have no difference whether they are based in the U.S. or not as far as U.S. employees are concerned. They will be responsible for the same tax issues as any other employer for federal, state and local payroll taxes. If you are working in another country for an employer in that country then it will be different.
The employer can never use your pay. YOU can be compelled to use your paid time ( a gift from the employer) for days you do not work. The employer can make any rule it wishes about that.
Employees do the work that generates the profits which allow their employer to pay taxes. But you will not find a deduction on the employees pay stub which reads, this amount deducted from your pay to cover your employer's business tax.
It Can depends on the company. Most do not and only begin pay when they walk into work and clock/sign in. They do pay if you are delivering or collecting goods and you have to drive around in your company vechile. BAd answer above. Even if the employer provides a vehicle for its convenience, employees are not on paid time when commuting to the workplace. No pay, no employer liability if injured.
No US employer can ever compel you to work for free. ALL work, without exception, must be paid. The employer can change your schedule, but must pay for your work.