如果这样做不合法,我就不帮他们了.
(It is legal if their money is clean, they can bring it in themself too, just need to report to custom; so I suspect they want you to be the middle man for some transfer. Then if you get inspected, I doubt they will prove the money is clean)
有点没明白为什么我有可能要付收入税。
It is your income (money comes IN to your account), IRS don't care how you spend it, they only care what comes in.