is there any other way of getting W2 form aside from the company i worked with?

again, you need to contact the employer for a copy
you can go to the SSA web site and see if there is a form you can submit to them for a copy of your W-2 but as yet I have never known anyone who was able to get a copy from that agency

You could get one from another company that you work for. However, if you need to claim more than is shown on your w2, then in the tax form, there is a place that you can add in other extraneous income. YOu don't need a w2 to claim more income. However if your current w2 is wrong, then you just have the company correct it.

The problem with wrong W2s is that the W2 information is sent to the govt directly from the company, so if you report something lower than what is on your w2, then, you will get audited. Really they are only looking for underpayment not perceived overpayment and that is the problem. You can't claim less because they will know and audit you. You can only claim more income but if you have income from multiple sources, you may not know what data they have on your income, so it is best to always report what ever you get, then do the long form to deduct expenses or other deductions. However never lie, that increases penalties when you loose your court case, if it goes that far.

No. The term "W-2" means a form from the company that paid you. If you get it from anywhere else in the world, then it's not a W-2.

no

from the IRS