Indeed, eliminating the possibility of future leaks.
I would also look at the two big screw caps at the filter head assembly, mine developed a big leak all of a sudden.
They are sealed with some sort of locktite type substance and they need heat to break them loose.
Yes again, and a Viton seal would be a good choice.
This is the thread I made when I did this eight years ago, and I just added some photos.
@gregma, the only place that had them would only sell a set of five, so if you are interested I still have some spares.