Um, What Will Happen If I Link My Steam Account With the EA app?

I'm curious because Origin and Steam were acting up for me (origin went blank and steam kept deleting my saves) and as a result to that, I decided to uninstall them, but I didn't realize that my dlcs on Steam would not transfer over (I had originally thought that if I had linked my Steam and my Origin account together that it would somehow, surely, transfer over to the EA app, but unfortunately I guess that's not an option). 

All I see from the EA's app is that the addon section for said game is labeled "Manage on Steam", so I'm curious if I can unlink these two accounts or not (I've heard mixed responses on it, so idk). Do I have to re-purchase them on EA? Will Steam's auto cloud feature effect my documented saves if they're linked? When I unlink, will EA recognize those specific packs from Steam and so I wil no longer need to have Steam itself installed if this said thing is possible?

I really just wanna download my content and play, but I can't find an exact guide or video tut on how to go all about it 😩. 

Thanks in advance!

Edit: I'm using Windows 10. My Steam and EA app accounts are updated.