will proseries professional require adobe or will it accept foxit as an attachment to e filing returns? will foxit be accepted by IRS and state agencies?

Foxit is not the File you will be handling. It is the tool you use to work with your PDF files, instead of using the Adobe product that works with your PDF files. You are never "sending Foxit;" you still are sending PDF files.

If ProSeries creates the PDF file, then there is nothing different here. The choice of which tool you use to open, view or Read PDF is yours. It's like the web browser. You might be using IE or Edge or Chrome or Firefox or Opera or Safari to browse the web. That doesn't change the internet. It changes your perspective, because you use a specific tool and someone else might be using a different tool for browsing.

Foxit isn't a Format; it's a program for managing pdf filetypes. Adobe is the company that created pdf and sets the protocol for how pdf is formatted. Any pdf program can handle pdf filetypes. You would need to know if the other program(s) you are using will support not having an Adobe Reader installed, though. Example: QB "calls" Adobe Reader directly, to launch pdf from the QB program, so having Foxit is moot. I can use Foxit for my own needs, but I also need Adobe Reader installed for QB to use it. The same is true for IE; I can use Firefox and Chrome for my browser, but QB requires IE to be enabled, because QB will use IE protocol.