[Steve Strzepek of BTTF]

I am having more owners in my league submit team exports to me for lineups and roster moves. I do not have the "password" function enabled. What problems could happen by not enabling it and doing imports ? Can owners edit player salaries and change ratings if I import one that they did that with ? Or does the import not load if they attempt that ? incapatable files ? Please advise how that works!