Tar will gum up a PC, and can, in rare cases, cause shorts. Mostly it will cause fan bearings to break, and reduce the efficiency of the cooling systems.
Smoke outside, go for walks, it's good exercise.
We're friends with the neighbors but the laws here about fences and gates are all from cowboys and indians times and can have no-questions-asked existential consequences.
That whole section of law frightens and confuses me. We had to draw up papers with our neighbor to let them use some of our back yard for a gate, and it took like, five fucking lawyers to draft an agreement where we were not ceding any land but they would not have to pay rent or taxes...