Dip direction is normal to the strike line and in the direction that the fault plane tilts downhill. Dip is the maximum angle between a horizontal plane and the fault plane in the down dip direction. The picture of bedding plane with strike and dip indicated on page 293 of your text may help to clarify the concept of dip and strike. The salt rises as a solid material much like glaciers flow downhill as a solid material. I indicated that the viscosity of both ice and salt was much less than that if rock in the mantle.
Salt is more viscous than ice by about three orders of magnitude.
This means that salt rises more slowly through the crust that glacial ice flows downhill. Salt does, indeed, rise because it is less viscous than surrounding rock. When salt penetrates to the surface it will form a column until rain water dissolves the salt but it will not make it to the surface in an explosive manner. Yes, the crest of the anticline was removed by erosion much like the anticlines on either side of the Mount Nittany syncline are missing.