^ I think the above two bits of text are fine as they are. You might say “and crossbows can not be reloaded” to make it complete, but the missing words are implied from the earlier part of the sentence. Or it could say “bows cannot be fired nor crossbows reloaded while engaged in melee”. In the second one, having or not having a comma doesn’t affect the meaning; it’s just a question of whether you’d want a bit of breathing space when speaking it aloud.
See a couple more minor text omissions below (both just missing an “s”).