I've landed successfully on the pavement in town before...
Actually got very lucky... lost my engine.. couldn't make it to base.. made an emergency landing in town and somehow managed to stop perfectly centered on one of the paved roads in town... LANDED SUCCESFULLY! Just before I was completely stopped, right as I was typing ".ef" I saw an enemy plane auger into a building right in front of me.
It was quite funny!
I have no problems with the current landing model - Fact of the matter is IRL you're much more likely to survive a landing on concrete than grass (Think about it.. if the plane is so banged up that it is uncontrollable, you're much more likely going to flip over onto the grass somewhere, or overshoot and crash N burn, or whatever. ) The fact is that if you have enough control of the plane to stop on the pavement, then your chances of survival are highest.. hence a successful landing. Also a "successful" landing, in my opinion, has nothing to do with aircraft condition... it has everything to do with if you can walk away from it or not, and not get killed by the enemy in the process.
Now the Ditch/Captured model I think is a little goofy. I think you should ONLY be considered captured if you're within a certain range of an enemy base (Radar Circle, for example) AND there is an enemy nearby. I don't believe there should be any proxy kills from a ditch/capture.. but ONLY in the case that the plane is fully stopped when you end mission. If you bail, then there SHOULD be a proxy kill if there is an enemy nearby.
Just my $.02...