As Ben mentioned, the ideal survival server you have described is available and is on the Pickaxis network. However this does not have towny. Hardcore is solely PvP and raiding. Unfortunately I'm not sure many people play on there any more. I would gladly come and play on there if you want to, and if you can encourage other players to do so.
I can't see survival changing. In all the time I have played survival nobody else has raised these concerns. I assume as they have stuck around on the server, as they enjoy the way it works. The problem I see is if a player is working really hard to make a town, but before they can their items and buildings get stolen and damaged. This would probably lose heart in it and quit. I know these sorts of servers are available elsewhere, it is just not what Pickaxis is or what it is about.
Go on hardcore and see if you can find all my stuff!