I recently filed a provisional application. The invention is in a late stage of development in terms of bringing to market. So my question is if I were to begin sale before a PCT is filed, but within one year of the provisional, would I still maintain my IP claim in the PCT? Also if I would in a country where the law is 6 months from disclosure (like China) would I have to file the PCT within 6 months of sale or would I have the full year from the provisional filing date?
To answer the question of title - Yes if it a very good provisional application, No if is done by yourself or for any other reason the PCT needs more detail or other new matter.
Under the terms of the Paris Convention, to which China is a contracting party, the first application in any Paris country for a particular subject mater can be used as a priority filing in any other Paris country to allow 12 months to file.
The six month grace period in China to file from when novelty is broken only applies in very specific cases. Not relevant in youir case if you file in 12 months since the Paris Convention provisions are such that novelty isn't considered broken by a disclosure if the first Paris filing is done before that disclosure.