Re crab/de-crab: very often it is being taught to land with crab, since the torquetubes in the gear have no problem handling it, and the risk of a podstrike is too great when applying C152 style x-wind landings.
Though a bit of aileron into the wind never seems to hurt either when winds are really stiff.
My Boeing book reads:
Sideslip only (zero crab) landings are not recommended in crosswinds in excess of 20 knots. This recommendation ensures adequate ground clearance and is based on maintaining adequate control margin.
and:
Touchdown In Crab
The airplane can land using crab only (zero side slip) up to the landing crosswind guideline speeds. (See the landing crosswind guidelines table, this chapter). On dry runways, upon touchdown the airplane tracks toward the upwind edge of the runway while de-crabbing to align with the runway. Immediate upwind aileron is needed to ensure the wings remain level while rudder is needed to track the runway centerline. The greater the amount of crab at touchdown, the larger the lateral deviation from the point of touchdown. For this reason, touchdown in a crab only condition is not recommended when landing on a dry runway in strong
crosswinds
Again, this references only to Boeing aircraft.