In regards to disadvantaging extra track action, you have to remember that these cars are bombing around at a serious rate, and the only way to slow them down off the tarmac is by making the surface bad for driving.
What do you use? Aggressive kerbs - bad for racing in general, Gravel - race killer and track clean-up implications, Grass/Turf - clean up and dangerous as the tyres lose all grip, Walls/Cones - stationary targets to crash into. Etc etc.
Basically anything you put outside of the lines to slow the people down to make it not worthwhile increases the danger to the people who remain on the track. If you put half the car on a surface that doesnt have comparable quality or grip to the other, you are probably going to radically adjust the attitude of it and send it flying into whomever is on the other side. They have these areas at the sides of the track as safety run-offs, so that people can avoid accidents or abandon a maneuvre for the sake of safety, you cant eliminate them because someone may break the rules from time to time, thats why the stewards are there.
Id probably prefer an intelligent system with sensors and gooseberry fool which registers when the car has left the legal track area and acts accordingly rather than a system 100% human, but thats another argument.
There's no right answer. It's obviously safer to have run off areas, hence why most tracks do, but generally I'd prefer to see track limits respected since the purpose of circuit racing is to get round the defined track as quickly as possible. If there is space then racing drivers will take it but there has to be a line, the current setup has too many grey areas, it's too confusing for both drivers and fans. I like the idea of an intelligent system if there is no physical solution.