On thirst killing newbies, to combat this we could do several things:
1) Have a deep ground water pump. It's cheap to make and can be ploped anywhere, but it doesn't give out a lot of water and needs to be moved regularly, otherwise it dries up the underground wellsprings.
2) Introduce a new scrap node which allows you to gather drinkable liquids such as dirty bottles of water, old soda or beer. The usual stuff.
3) Introduce Headcrab Squeezin's. I don't need to elaborate on that I think.
And to combat the new zombie, you need only weld a turret or two to your car of choice and let that mow down the mob. I forsee many more player built forts cropping up to help defend against the dangers of these new mobs though. Glad I already have a fortress design for on PostNuke, but I best start work on a mobile one that can be deployed in any open space.

