According to the rules of Scrabble, the prefix dis- would not be a valid word to play.
However an argument could be made that DIS as a commonly accepted acronym (for example: Defence Intelligence Staff or Daytona International Speedway) could be a valid scoring word.
No. Oz is not a valid Scrabble word.
No. Qu is not a valid Scrabble word.
Yes. Speculate is a valid Scrabble word.
Nope. Indew is not a valid Scrabble word.
No, "wind" is not a valid base word that can be combined with the prefix "dis." The prefix "dis" typically combines with words to indicate negation, reversal, or removal of the base word's meaning, such as "dislike" or "dismantle."
Yes. Ex is a valid Scrabble word.
yes Gaza is valid scabble word
Unfortunately VAX is not a scrabble word.
No. Xe is not a valid Scrabble word.
no
No, 'xo' is not a valid word in Scrabble. 'xi, xu, ax, and ox' are some of the valid 2 letter words in Scrabble containing 'x'. 'Xo' is valid only if you are playing Clabbers, a variation of Scrabble where and anagram of a proper word is allowed.
Yes, "ova" is a valid word in Scrabble.