less polygons = less processing power required to deal with them
smooth tool quadratically interpolates between points, ie it makes it look round between verticies
so to make a hard edge stay hard but not so hard that the model looks sharp just add more edge loops. it increases your poly count but maya can handle it.
lofting creates NURBS by default i think. NURBS are infinately curved (no matter how much you zoom in it's always round)
when you convert it to polygons make sure your construction history is on and then you can change how the conversion was done after it was converted. you can change the spans, the span type, and all sorts of other things
you can fake the roundness of a polygon model by softening the edges (or soften normals, same thing), i'm not going to explain how that works because i've done it enough times on the forums already :p
if you need to know google it or search the forums
that's a "Ch" pronounced as a "K"
Computer skills I should have:
Objective C, C#, Java, MEL. Python, C++, XML, JavaScript, XSLT, HTML, SQL, CSS, FXScript, Clips, SOAR, ActionScript, OpenGL, DirectX
Maya, XSI, Photoshop, AfterEffects, Motion, Illustrator, Flash, Swift3D