Proper Paragon driver versions to share Office files between Mac & PC

Hi:

I am not a technical user and I am confused about Paragon drivers to be used with a new Seagate Backup Plus Ultra Slim 2TB drive. I’d appreciate some help.

I want to use this Windows formatted external drive with a Mac now using OS X 10.9.5 (Mavericks), to copy to it Office files created on this Mac. I also want to share this drive on a PC (with Windows 10) and be able to read and write on the PC the Office files created on the Mac.

I was advised by Seagate to reformat the drive using Mac OS Extended (Journaled) format; then connect the drive to my PC and download/install the Paragon Driver for Windows ( HFS4WIN.msi).

I plan to upgrade soon to OS X 10.11.6 (El Capitan).

Two questions:

1. Is the above procedure as advised by Seagate the correct one to enable me to share Office files between the 2 computers?
2. Is the same Paragon driver version compatible with both Mac OS versions (OS X 10.9.5 and OS X 10.11.6), or if not, what version will I have to download after I upgrade the OS on my Mac?

Thanks