Turbulators, slots and slats are all somewhat different beasts, and are used in a variety of ways on modern aircraft.

Turbulators, Vortex Generators, Vortelons are all in a group that, by inducing vorticies on the surface, prevent airflow seperation. The increased energy on the surface is used to increase control responce (when used in front of a control surface) and in the case of vortex generators across the entire wing, increase lift at medium to high AOA flight.

Slots, both fixed and movable, allow high pressure air from the lower leading edge to pass through to the top side at higher velocity than the natural airflow over the wing, thus allowing flight at higher than non slat wings. This would happen with no increase of chord.
Slotted flaps also take benefit from this principle.

Slats work both in the slotted role and the "sealed" role. The sealed role is an increase in chord, but more importantly is a huge increase in camber, thus increasing lift for a given airspeed.

As for snappy caps, I'm in the make sure it's straight and balanced camp. I also like to do power off stalls to see which wing drops to look at the airframe and exclude any thrust questions before chasing power on snaps.

Les