It is also older the our sun. Studies have placed Tau Ceti to be anywhere between 5.8 to 10 billion years old (these great discrepancies are a result of differing studies using differing methods). However, that doesn't mean that the star wasn't violent in its past - perhaps enough to sterilize any planets orbiting it. In addition, it possess a dust and debris cloud starting at around 6 AU from Tau Ceti and extending out to 16 AU. This cloud is ten times as dense of Sol's Asteroid Belt, being more analogous to our Kuiper Belt. Unless there is an as of yet undetected gas-giant deflecting errant members of this cloud, impacts will be in high supply for the inner planets of Tau Ceti - including e.
As for e's habitability, this paper
on planetary habitability casts some doubt on this idea (it is discussed on pg. 3-4), summarizing that planet e and probably planet f are super-massive Cytherian-type worlds due to the amount of radiation they receive from Tau Ceti in their current orbits. Of course, we cannot rule out Venus in our own solar-system having life in its clouds or deep underground, but it is generally thought of as a remote possibility.