A) The point under discussion was security on the way out, not on the way in. Since you were just passing through, perhaps airport security was given a heads up to look for something specific to your flight? You did say you were coming from Amsterdam, after all. Arriving into KL from Hong Kong, my flight had no additional screening, and immigration procedures into and out of Malaysia are the easiest I have ever dealt with in any country (you don't fill in any paperwork, they take it all off of your passport matched up with flight manifests). For reference, I am at about 1.8M air miles (not including all the free trips I took) and in the process of filling up my 4th extended passport (where they add an additional 24 pages). Regardless, concourse security at KLIA was the laxest I have ever experienced post-9/11 anywhere in the world I have traveled.
B) You must not have flown into KL International airport, there are zero mountains within 30 kilometers of the airport (and those are big hills, more than mountains) and zero mountains on any approach path that doesn't try to land at 90 degrees from the airport (typically an unhealthy approach to any runway). Or maybe you have a different concept of what is a mountain from me.
C) Those hard landings are not uncommon when pilots allow the ALS to land the plane with even mild wind shear present. Or poor pilots blame the ALS, at least.
D) Drug trafficking means possession with the intent to sell. Mere possession of small quantities of heroin or marijuana is rarely considered trafficking, even in Malaysia.
Since you can't do it anymore in reality, find a flight simulator that models the old Hong Kong airport runway approaches, or find YouTube videos that show airplanes passing at close to the same levels as high rise building while performing 40-60 degree turns to line up with the runway (there used to be a rooftop restaurant famous for plane watchers) on the top of mountains, then having to dive down rapidly to not overshoot the runway (a low fuel, passenger loaded 747 at 225 tonnes needs roughly 1675 meters of runway to land by the book IIRC, and the longest runway at Kai Tak was 1664 meters and those 747s were landing all day long), frequently while crabbing heavily to deal with heavy cross-winds. I can say I miss that experience... now. Ex-Navy pilots said it was the closest thing to trying to land a 747 on an aircraft carrier with a cross wind that they could imagine. Wikipedia has a good explanation of various approaches.