A : Yes. If you send a value for a field, it will override the previous value for this field. However, Akeneo data should always be the accurate one!
A : If you want to check the compatibility of the module you can now go to this section.
A : Depending on changes added on Akeneo and/or Magento 2, PIMGento2 (API) can be compatible among versions, but be sure compatibility remains our top priority for the module. You can check our roadmap if you want to know more about the future of PIMGento2 (API) !
A : Yes PIMGento2 (API) can handle multiple websites and multiple stores.