Dead Ringer combined with the defib may cause issues, trying to defib a fake body might cause issues, and definitely confusion for new players, but the item itself is good.
Detectives don't need a defib IMO, a revived detective not only has all the info they saw when they were dead, but also a radar to see all the people who are t's.
Not bad suggestions, I like the sound of the Dead Ringer but I don't think either are necessary.