Vehicles - check your options. There's a new key binding available to start a vehicle, and I don't think it's bound to anything by default. So you have to set it up to be h or something, press "use" to get in the vehicle, and then another (h or whatever) to start the engine.
I've found vehicles to be really effective for some situations - you can only use a pistol while driving one, not a rifle (makes sense to me) but that does mean you can do drive-bys with an unsilenced MP5 - an excellent combat tactic, especially against small squads. You can run them over, shoot at them, and are much harder to hit yourself. Oh, and the APC is really excellent protection from being shot at - if you manage to steal it (from the soldiers by the outpost in Cordon) you can take out pretty much anyone in that map at will by running them over. This makes stealing documents from the outpost or defending the stalker camp easy and fun, instead of hugely challenging and always ending with you getting shot in the back as you run away.
As for surviving blowouts, I think I read something somewhere about just needing enough cover that you don't get rained on, and you won't get the lethal radiation or anything. I remember joining a bunch of stalkers hiding in a little wooden hut to survive a blowout all the way up in Army Warehouses, and never lost a point of health.
Or you could wander around gathering Fireball artifacts and stick 10 of them on your belt. That ought to make you impervious to most radiation.
Oh, and booze does work on radiation, but anti-radiation drugs are better. Available for free from some dead guys. You can usually pick one or two up by going to the Garbage with any sort of rifle and picking off the pistol and shotgun armed bandits who attack the factory (this is also rather cruel fun, especially if you have a decent rifle with a scope).