water has leaked into the sparkplug holes or into the alternator use startdryer a spraycan you buy at any gasstation or a garage
What would help would be an articulate question. Does "lose power" mean a loss of voltage/current, or a loss of engine power (horsepower/torque)?
Yes, but make sure to save your work frequently, as the power may unexpectedly go out.
Low fuel pressure
could be a possible blown head gasket
Yes it would and how big the vacuum leak would determine how bad.
applying pressure to the brake pedal
Check the fuel filter and catalatic convertor.
yes it will not only lose power it will run rough in some cases not run at all
Yes it could and it will cause rough idling and a missing when giving it gas.
No. Seat belts are not connected to the engine or power train.
check compression in cyclinders or catalytic converter may be stopped up.
A malfunctioning oxygen sensor can cause the engine to be low on power.