A simple Caitlyn addition that will make her W just a bit less cancerous...
Have a CD on how often you can set off traps.
Example: Enemies recently trapped cannot be trapped again for 12/10/8/6/4 seconds. Or 12/9/6/3/none. Just so she can hit you once, but can't spam-trap your tower and constantly deal 300,400 damage every 3 seconds.