All of the symbols are optional in J, except for =. and =: which are used for assignment. If you don't like % for division you can define

    divide=: %

and then only use divide. If you don't want to come up with your own names for all the built-in functions, you can just use the names suggested in the vocabulary (J's main help file). If you don't want to write all those definitions to give names to the built-in functions, there is already a module in the standard library that does it for you.

If you do decide to program in J, however, I recommend you just learn the symbolic names, they're so much shorter and fun. :)