Re: Propeller pitting
The red in the bolt holes appears to be ink, like from a Sharpie pen. I think the previous owner did that, because he left me a number of spare anodes and they all have that red in the bolt holes. I have never used Lock-Tite - doesn't seem necessary for the cone anode. I don't have an anode on the short amount of exposed prop shaft forward of the propeller. I'm not sure one would fit there but I'd have to have it in front of me to know for sure. There is another anode at the base of the rudder skeg (see before and after photos), and I put a magnesium one on there as well.
Boatpoker's comment about electrical contact is very interesting... I recall using a wire brush to clean off debris after removing the previous anode (zinc, which was half gone), but maybe I didn't get enough off. If a wire brush isn't enough to get it clean, what would be better? I'll get my multimeter and check the resistance in the meantime.
Regardless, it looks like I'm going to end up sending the prop in to PYI to get it overhauled...