first of all, like donal says.. contrast (the everall contrast of the print) is usually a matter of taste, mode and aesthetic statement.
sharpness deals with the countures of the lines, details, objects etc etc.
optics plays the most important role in sharpness. but note, scienifically the sharpnes is determined by contrarst (the kind of contrast which is used in the mtf tables - lp/m). than of course comes the importance of the film used, and the developer.
what, do u want to be sharp, with the capable optics ??. do u want sharp finest details - than it is a very slow film very well exposed without the vibrations, and very well developed. do u want the general counturs of the object -than the faster films will do the job.. etc. so even here there are some kind of sharpneses.
contrast in the print is devided mainly in three.
the overall, the local and the micro contrast. the micro contrast deals very directly with the sharpnes of finest details.
the main importance of overall contrast is the general appearance. actually the overall contrast is a part of the composition - no matter what is your object and its positioning etc. it puts the eye into some tention - which many times means - interesting, emotional etc.
the local contrast is the prime thing in creating the 3d effect on the 2d paper. the local contrast creates the tonal difinition.
with the micro contrast u can view the finest and the smallest details on the pront even from the close exemination.
those are lots of aspects, while every photographer has his own relation to those aspects. this way actually we create our visual and material language.
of course there are other not less important aspects in creating style and languege like subject, the visual and cognitive perspectives etc, but those are another issues.