A temp gauge is most useful in order to prevent motor damage, the method you said you were going to use it for. Just don't fall into the trap of becoming the dummy that says, "on a day like this, this particular engine will work best at 246 degrees while idling for 5 seconds in the shade of the pit area (
)." Don't be that guy. Even if your temp gun tells you that your engine is running at an appropriate temperature, your engine still could have problems. A temp gun is a tool that can't do everything, but can help you tune your engine and allow you to trouble shoot problems much quicker than if you did not have one.
I would suggest a temp gun to anyone that could get one without having to really go out of their way in order to obtain it (mow 10 lawns, wash 7 cars and 4 vans, etc...). The raytek temp gauge you can usually get from a hobby shop is a good and very popular choice.
Pops,
I know OFNA has one of those fuel filters. Unfortunately, the only description I can give of it is that it is on of the 'big' ones that they have, not the 'skinny' one. Hopefully that might help some.
Supernitro17,
that is what everyone does to the 15fe... and boy is it fun
.