I know this is a really old thread, but have there been any changes in the last 10 years?
Any trouble for US citizen (US passport) to enter Mainland China and Taiwan? If one country has a problem with the other, would it matter what order they were visited? There's already a Mainland China visa in the passport.
This may sound silly, but I don't know....does the passport get stamped when there's a visa in place?
Thanks.