The hard cranking is probably because the valves are out of adjustment, I set most Briggs to .006 on both, to set get engine to top dead center on compression stroke then turn engine 1/4 inch to the right to get past compression release.
The smoke could be piston rings are worn or valve guides are worn, I would not worry to much about a little smoke at start up, just make sure you check oil before each use and keep it to the full mark. (do not over fill)