Question Atm i use google drive and want to move over to seafile

Question Atm I use google drive and want to move over to Seafile. But when I test the demo it won’t open my docs files. I see that seafile uses office to open docs (Also what some people call word files) Is this just a problem with the demo or is it just how it is since the file was made on google drive.

Also, do I need to pay for office to work? Since all of my files are currently hosted on google drive and are for my gaming community.

Also, can I make a folder and give perms to my staff to open that folder and upload and edit documents. But for normal members not have access at all to seafile but if they get a link they can open a file say a docs folder. Just like how google drive does it. I can make a folder grant access to other google accounts and they can upload both private files just for staff and public files for everyone to access if they have a direct link.

I hope everyone understood my question and also I have no idea what category to post in. So please change / move it if you know where it should be.