If you open the hood, on the passenger side, you can see two belts. The one at the top drives the alternator (top pulley) and water pump (pulley below the alternator), and the compressor (A/C) at the bottom. The belt towards the ground and way in the back (harder to see) drives the Power Steering. You can access this by removing a panel under the car. There are three bolts on the pump, the top one cannot be removed but must be loosened if you are replacing the pump.
Of course. Heck you could convert it to a diesel if you really wanted to.
yes
In the gas tank. I have 2001 Echo.
2001 Toyota Echo doesn't have a timing belt.
http://www.carspace.com/guides/Toyota-Echo-How-to-change-oil
http://pdftown.com/2000-2002-Toyota-Echo-Service-Manual.html
no idea it is probably using the brake fluid
3.5 Liters
Depends on the fluid. 3.6 liters for oil.
manual recommends Dot 3.
timing chain.
see link