Buy a can of cleaner and add 89 Octane or higher gas, you should be able to clean the throttle body.
The transmission flush cost $39 bucks here in Georgia, so I do it every 30 k miles.
Coolant flush is $69 here, you can DIY.
Dont think you need to lubricate all hinges and locks at this moment.
Our 2004 Quest will pass 140,000 miles in a week. Never had any problem except the back-up sensor needed a new buzzer, and change front lights.
Another reminder: the original battery is bad and only last 3 years. This happened to our another Nissan car. So you might need to change the battery very soon.
