With any used care the it's always safest to have the routine stuff changed, at least as gradually as you could afford just to be sure.

You only know how old a part is, if you have the service records, or if you put the part in yourself.

My other suggestion would be to immediately:
Check the battery -- meaning take it somewhere where they will check how much charge is left. It too can look new and be the original battery that came with the car.

Have the tires inspected -- including the spare. Make sure the tread is good all the way around. Take the wheels off if you have to.

Also, have a service center check any open recalls -- including the headlight switch recall, srs-air bag recall, a recall for the turn signals, and there was a service bulletin for the front wheel bearings (wheel hub kit). All covered under a VIP warranty, which should last up to 100k, or sometime next year.

Just change the timing belt just to be sure. If you bought the car from a dealership, never assume they did anything to the car. If you bought it from a person, just call them and ask. I've personally traded in cars at dealerships where it was out on the lot the next day, w/o as much as a vacuuming.

With 78k on yours you should have the VIP warranty still in effect, it transfers over. Take advantage of it for the recalls and service bulletins above.