Conventional English is generally not well disposed toward genderless discourse. Though gender usually does factor into verbal communication, it needn't be so in written communication. A difficulty in a place like this is that our exchages seem to often fall somewhere between verbal and written norms or conventions. Personally, I think not knowing the other person's gender leads to a more considerate conversation. As to the use of expressions regarding "balls", the usage is metaphorical, not anatomical, and gender seems thus unimportant to the communication. Excepting, of course, that the speaker might choose a different metaphor when the other person's gender is known. :-)