"si possono condividere tra più tenti" should be → "si possono condividere tra più UTENTI".
"tenti" in Italian is a verb, but in this case it has no sense. The meaning of the correct phrase sounds like "they can be shared among multiple users"
"mi sembra poco efficiente che le password sia sparpagliate un po' ovunque" should be → "mi sembra poco efficiente che le password SIANO sparpagliate un po' ovunque".
It is incorrect because the verb is in the third-person singular, but "le password" (= the passwords) are plurals, so the verb should be in the plural form.
I've discovered 2 errors that were not detected: