BEAST WARS is a character-based science fiction show with a lot of action. Our characters are intelligent beings first and foremost, even though their natural state is robotic.
We want these characters to have distinct personalities and even senses of humor. We have to care about them, to enhance the jeopardy and give the show depth. There should be personality conflicts not only between the heroes and villains, but within the Maximal and Predacon groups themselves. There should also be bonding moments. We want this to be a show with good acting and good character -- the CGI animation has proven its ability to support that.
Even during the action scenes, there is room for character and humor. The animation industry already has plenty of shows where the heroes to nothing but shout commands at each other. Remember, these fighting machines may be impressive when in battle mode, but they are still intelligent beings. They still have their personality quirks. Use them!
At the same time don't use animal mode just for comedy. Optimus is Optimus whether he's swinging through a tree or launching a missile at Megatron. And each unique animal form has abilities which are often more useful than their robotic forms.