HI Eric,
I'm not in a very dewy place, but my 12" GSO did get a bit of dew on the secondary occasionally before I did the mods described in
http://www.iceinspace.com.au/63-400-0-0-1-0.html
In fact, I only did part of the modification. I put the baffle inside the tube about 1-2 cm above the primary (using thick self adhesive door sealing foam tape) to direct airflow across the front of the primary and I put the neoprene gusset on the back of the tube to stop air from the fan bouncing off the back of the primary. I left the existing fan in place as vibration was not an issue. Never had dewy optics again. It also dramatically reduced the length of time for the mirror to cool sufficiently for good seeing. I'm not very skilled with my hands and it was a very easy mod for me.
Finderscope? Just keep putting the caps back on it when you're not using it in the observing session. Dew covers can be bought for Telrads or put a small plastic bag over the business end when you're not looking through it. This all sounds a bit cumbersome, but it becomes second nature very quickly. I don't even know I'm doing it these days.