1 - Some people simply don't think that way. And no matter how often you hit them over the head with "HAHA! You didn't say you were searching under the mattress so no pearls for you!" they won't start thinking that way.Clearly your mileage may vary from mine. While you see juvenile bickering and pixel-bitching, I see players actually interacting with the description the GM gives for the room and the environment. I've seen a number of cases, in a 3e+ world, of players saying they're taking 20 searching the room without any indication that they're really thinking about what the room is like. The searching rules (spot, search, perception, whatever) may make it easy to use a PC's own abilities (which will differ from the player's) and help a goal-oriented/kill and loot style of play flow efficiently, but it's very easy to fall back to a game that doesn't involve rich interaction with the environment.
2 - I personally am long passed done with scraping every nook, picking every cranny, and reducing the furniture to splinters in case the desk had a false leg with a few coins hidden away in it and basically spending thirty minutes per room crawling through a dungeon. Give a 30 second die roll , a loot list from the DM, and let's move to the next room.