In my only playthrough so far I told Gale to leave because I was playing on the basis that my character was afraid he might explode at any moment without warning (i.e. against video game rules). It was a tragic moment in the plot but otherwise I don't feel like I missed anything, except for not having a wizard and not having Gale's storyline. However I will play a future game and keep him.
Okay so it doesn't result in catastrophe? Whew. I'm not sure how he solves his little problem without the player's help but at least I'll be able to finish the game reasonably. And yes, definitely play a future game with him in the party, and bring him along a lot - his comments are not only funny and unique but sometimes give really interesting and helpful information. The only time I'd suggest you NOT include Gale in your game is if the idea of him flirting with you is really disturbing or game-breakingly irritating to you for any reason.
