If cab driver's behave to customer is friendly and helpful than we need to tip him for his good work but if his behave to customer is rude than customer don't need to give tip to that cab driver. In-sort giving tip to cab driver is depends on driver's behavior, services that they provide to customers.
Do taxi drivers like long fares?
Multiple short rides may make more money on paper but hustle and bustle is taxing on the driver. All drivers I have known prefer longer rides. Many taxi drivers often have a daily target to achieve after which they'll just hang their gloves and call it quits for the day.