I wouldn't change a single thing. Hell, i would add ONE episode. It would have to be and OVA but what the hell.
Ash and Brock ditch the girl of the month and go to a laboratory where nurse joy, officer jenny, and some scientist, perhaps professor ivy, are studying spores excreted from a sick gloom.
Gloom sneezes and releases a strong powder while everyone is in the room.
It would end similar to that one episode of Moyashimion with ash hanging naked from a rope and brock with his head in some jar, except all the scenes inbetween would be animated.