a few ideas to bat around
The first is easy, if say your searching for the right base to attack and you accidentally deploy your default troop, there should be something to nullify the action. I really hate losing 20+ trophies to an accident.
Modify the trophies so that they reflect the current town hall and activity. What would happen is you get a set of trophies based off of where you are on a particular level of upgrading a th, while the current trophies act as they do. What this would do is when attacking someone, it looks at your th trophies and shows you people to attack based on a range of your th trophies and your active trophies. This would actually give people a chance to actually hit people that are around your strength rather then getting clobbered by an uber person that's farming far to low