why doesn't elemental damage actually function the way the elements should?
if i missed something just let me know
if i am not mistaken fire from magic or alchemists fire actually continue to burn or why doesn't acid from magic or acid flasks melt through materials like metal?
why doesn't electricity damage travel to touching targets or electrocute any one standing in water?
or cold damage freeze liquids?
again if there are rules to say these all accrue just point me in the right direction.
Because the rules are abstract and it would be too much to have rules for exactly everything. But you can always house rule if it's a priority for you - that's one of the best things with d20, that it's so easy to modify!
Note though that alchemist's fire does continue to burn, and in the rules on hardness IIRC it states something along the line of "some materials might be extra susceptible to certain types of damage, ignoring hardness". I think certain types of acid might be excellent candidates for ignoring the hardness on metal or wood.
And some things you just have to handwave. Even if it doesn't say specifically how much liquid you can freeze with a ray of frost, you as a DM can of course allow it to keep the PC's drinks nice and cool. That's assumed, more or less.