The top scrabble letters for points are Z X Q J , name a word with one of these letters

[MyCheeryPearlTraybake]

I will start
Excellent

No, you can't use Zion or Zionist, they're proper nouns.
I love some of these two letter words, very useful! I can never seem to get rid of the letter J when I get it.

Quetzals

I like the better J.
Jo
Joe
Ja
jog
jot
raj
je
jam

my best score ever was 96 .

As I said above, I hate ‘C’ closely followed by ‘V’.

zilch
zinnia

Do the rules forbid "Xerox"? (It's some years since I've played.)

Yes, it's allowed because it's no longer a trademark so doesn't begin with a capital letter. You can use it as a verb or a noun.

Juxtaposition?

Quartz