I would say that amount of rust is normal for that age of car. Keep in mind a good number of those pictures posted are of the skid plates, which can be replaced for not too much $$$ if you want to go OEM. that fuel tank skid plate has seen better days, replace with a full gas tank skid if you plan on doing some trails (I used an OEM trail trim skid on my limited, spent a couple hrs cleaning out the unused bolt holes though because I too live where road salt and brine is used all the time)

poke around with a screw driver on some of the more rusty spots, does it go through? I'd also check the spare tire and make sure the chains haven't rusted together rendering its use inoperable. I just replaced my spare tire pulley assembly for that exact reason - they don't use the chain anymore, at least the new assembly I have doesn't use a chain