well,"comment allez vous opium" is good french,but u'll say that to someone u don't know,it's the very polite version,u could say "comment vas tu opium"
same for 2nd sentence,not "vous etiez" but "tu etais",and not "dans l'OD",good is "dans OD"
last sentence is corect
,i will give a 7/10 coz of the "vous" form 
same for 2nd sentence,not "vous etiez" but "tu etais",and not "dans l'OD",good is "dans OD"
last sentence is corect
,i will give a 7/10 coz of the "vous" form