While your first two approaches (booking all the seats on one side of the aircraft and running around) might work, they require a rather large amount of people to do so. A few men with steak knives really shouldn't be a threat to the safety of an airplane either.
Setting fire to a toilet aboard an airplane, besides being surprisingly hard to do in the first place, is rather unlikely to cause significant damage. Opening the doors while the airplane is moving at any significant speed, let alone altitude, is physically impossible (Unless your name happens to be 'the hulk'). As soon as the airplane takes off and external pressure starts to plummet, the door is forced into place by the pressure of the air inside the aircraft.
As for those doubting the explosive properties, mixed properly, the hydrogen peroxide would release a substantial amount of oxygen when the detonator goes off. If the pressure of the shockwave is sufficiently large, that will set off an explosive reaction between the sugar and the oxygen released by the hydrogen peroxide.
It's not a very potent explosive, but it is relatively easy to make and, with the exception of the detonator, pretty much safe to handle. The pressure build up inside the bottle is unlikely to be much greater then the pressure built up inside a bottle of carbonated drink when shaken viciously.
As for those implying that a terrorist wouldn't be opposed to drinking some of that mix to prove its safety, think again. Drinking a solution with only a teensy amount of hydrogen peroxide will almost certainly cripple you pretty much instantly, as that stuff is extremely aggressive. So aggressive in fact that very mild solutions of it are used to bleach hair.
Can't say for certain that would be true of all liquid explosive mixtures, but since an explosive requires an effective oxidiser, it's safe to say most of them would be quite nasty in contact with the skin. And very rapidly so.