One more thing about ticks, they seem to really like pine trees. I don't know why. Maybe it's the deep pine straw underneath them that they like to breed in, or the rough bark to hide in. But what ever it is, I've known people to cut every pine tree in their yard trying to get rid of them. But hopefully that's only true down here and doesn't apply to your kind of pine trees.
Hmmm.... Well, ours are firs, not pines... but it could be the same features apply. I'd think if trees and bark was all it took for them to survive, we'd be loaded with them. If I wasn't more worried about poison than I am ticks... I'd spray there. But I spose the area right around the feeder gets so many birds that any ticks that drop off there would just get eaten.