A quick search suggests that both of these are purely aesthetic problems; they cause no long term damage to the plant because they generally develop late in the season when the bulk of the contribution to growth by the leaves has already occurred.
I couldn't find anything on the the fungus/spores surviving the composting process, but I assume they most likely will since home compost heaps rarely get hot enough for long enough.
Either way, they seem rather prevalent anyway, so I personally wouldn't be too hung up about it since you can't control the winds blowing them in from your neighbours.
