This is not completely accurate. I am not a tax attorney but go through this every year. First, you can take the foreign income exclusion only on income that has been taxed by the foreign country you reside in. Second, you can't exempt taxes on that $100k, but you can for anything above that; alternatively you can just exempt taxes for everything and not take the exclusion (works out if country's taxes > usa taxes, really, the exclusiom just works out for low tax countries like Singapore, Hong Kong, and Switzerland).

Also, the income has to be sourced in the foreign country, if it is sourced in say New York you can't magically tansfer those taxes to another country without incorporating there.

You do not have to pay payroll taxes. When living abroad, some treaties allow you to pay them instead of local ones, but without a treaty you just don't pay. Of course, good luck ever collecting on your chinese social retirement account.