Change it and the water pump.

 

1. Should I really worry about the belt being deteriorated due to age?

Instead of worrying, I'd change the belt.

2. If I change the belt at 12K miles, do I also need to change everything else recommended (water pump, tensioner, bearings,)?

I'd be tempted to change the belt, water pump, all fluids, any cam seals that may be dried up and weeping, the crank seal if it's dried up and weeping, the thermostat since the water pump will be out anyway, and the two external belts. I'm torn on the tensioner so IDK about that. Do the math and see.

3. Are the high performance belts made by Greddy and HKS worth the extra money over OEM?

When people write "performance" I read "imitation" or "fake" instead. Don't use imitation parts.

Use authentic parts.

I used to use OEM-style Gates but their water pumps aren't to my liking any more (a Gates pump failed on me) so I've switched to Aisin. I'm coming up on another belt change myself and I've decided to stay with Aisin.

 

Thanks for all your input. I am going to start gathering parts and finding a decent torque wrench.

 

With 12K I would just put a new belt. Of course check for any leaks while your in there.

 

I made a homemade tool to hold the cam relationship on the drivers side. Makes it easier when installing the belt

 

That's very nice!

 

Wow! Flawless06 I’m sure! I thought I had something special with my 06 since new and just about to hit 90k. I agree with sd gr, if you’re worried about it then change it. I guess that means I’m way overdue for belts, clutch, etc, etc, etc since never done.