There are squat toilets in some areas of Pakistan too (at least in Karachi), but fortunately it never got to the point where I absolutely had to use one :p
Driving is really strange out there. There are lane lines painted on roads, but nobody stays in them. Like you'll have one car halfway in one lane and halfway in another, sometimes blocking traffic in both. Instead of using turn signals, people will honk to let others know that they're moving to a certain area. It's almost as if drivers, not pedestrians, have the right of way - it's common for drivers to honk at pedestrians to get out of the drivers' way while they're crossing the road (while there are hardly any intersections to safely cross with) -_-. Finally, when traffic is light, people will drive slow and take their time with everything, but when traffic is heavier, people will want to go fast, cutting each other off, squeezing into empty spaces, etc.
I guess this isn't so much of a custom, but a political corruption issue, but the power goes out there almost every day, often multiple times and for longer periods of time in poorer areas. Even with a backup generator running, the heat and humidity make power outages difficult to deal with.
In most places, you have to haggle while shopping. The people selling things often try to rip you off if you seem like a foreigner, and will sometimes outright lie to you about certain products while acting as if they're being completely honest and helpful. Once, my brother wanted to buy a video game. Even though there were obvious issues with the game (the box said "Game Foy Advence" instead of Game Boy Advance, had other grammatical and spelling errors, and the box art was washed out), the guy working told us repeatedly in a smarmy voice that he had tested it himself and it worked fine, and that it was a legitimate game. My brother decided to buy the game anyways, but that's a different story -_-
People there sometimes just jump into large bodies of water without thinking about the quality of that water. It rained heavily for a couple of days, and during that time the lower areas accumulated a lot of water mixed with the dirt and garbage from the streets. People sometimes swam in it. Similarly, sewage drains out to the ocean, yet if you go to the beach you'll see tons of families going into the water. It would feel nice after having to put up with the weather out there, but I would think having all that nasty stuff in the water would deter more people from going in.
I doubt most of these are unique to Pakistan, but they're probably different from what most EoFF members are used to :Oo: