Time and how to get to and from Jing'an Temple

The time is tight. If possible, you are advised to make a visit next time. But if you insist, here is the quickest way: take Maglev Train and get off at Longyang Road Station first. Then tranfer to subway line 2 to arrive at the Jing'an Temple Station, Exit 5. After arriving, walk north around 230 yards. The duration is about 35 mins. The return way is the same.

Do you have any other suggestions to have a little look at some Chinese culture in that 5 hour layover ?

For 5 hours, it is best to stay in the airport. There are some stores with souvenirs and handicrafts. You can have a look at Chinese culture there. You can also buy some souvenirs.