> If I use it only as a verb can I write {tlhIHchuq SunovchoH} ?

No.  I can't imagine what a type 1 verb suffix on a pronoun as "to be" might mean.  "You are each other"?  Even if so, how would it relate to the second sentence?  "You are each other you begin to be foreigners."  Why not, {SuSovchuqchoH}?