I don't fish for smallmouth but I can tell you that a bass will bite a jig/craw lure even if there aren't crawfish in you lake, while the lakes I fish have crawfish (I just don't believe there is a lot of them) I still catch tons of bass on jigs and craw soft plastics.
As for your Jig questions they can all be answered if you search for previous threads on this site, tons of good information!
http://www.bassresource.com/bass-fishing-forums/topic/12403-jig-fishing-questions/