lol I love the idea for evil toddlers, though even good toddlers climb on furniture and get into things. Perhaps though, they could steal another toddler's bottle, or push them, or whack them (like toddlers do, not like full grown sims slapping or beating up). And they could bite
Come to think of it, sims should get a 'bitten' debuff when bugs bite them too.
What I was thinking of though, well actually my daughter gave me the idea, sims should be able to just ride their bike around in the park or at home. And hang out with other kids on their bikes. And definitely should always wear helmets!!!