No such thing as a stupid question. The thermostat is on the passenger side of the radiator. It is the white plastic egg shaped thing that is at the 3-way connection between the the bottom radiator hose, top engine, and water pump. It is just held in place by the hoses and clamps.

Try the wires yourself it is really easy. The only difficult part is working in the tight spaces but it still boils down to unplugging and then plugging in 8 wires. Plugs are easy as long as they are not stuck in there or the threads are stripped.

I'm not sure but I think you have to replace the whole fuel pump as the pump and sender unit are in one module, someone else will chime in. That is also pretty easy DIY. You access the pump from the cargo area, you don't even have to get dirty.

Edit: Also forgot but your coils are fine. Don't replace them unless you have to.