No. Cie is not an acceptable Scrabble word.
No. Excelsis is not an acceptable Scrabble word.
No. Viz is not an acceptable Scrabble word.
Abbreviations are not acceptable in Scrabble.
No. Wop is not an acceptable Scrabble word.
Yes. Jo is an acceptable Scrabble word.
No. Fo is not an acceptable Scrabble word.
No. Eariest is not an acceptable Scrabble word.
Yes, "nus" is an acceptable word in Scrabble.
Yes. Re is an acceptable Scrabble word.
Yes. Moot is an acceptable Scrabble word.
In my eyes yes RN is an acceptable scrabble word.