Buy yourself the accessory grip, mount the camera to a beefy professional grade tripod, and put a compendium lens shade on the lens and much of your image problem will be resolved.
There 'is' however something of a stigma to shooting for pay with entry-level equipment,and it basically revolves around shooting with equipment that is very similar to what your non-photographer clients might happen to own. While individual clients in some areas might not are what you shoot with, other people who buy photographs or photographic services have expectations of pro-level equipment in the camera, lens,and lighting/grip field.
Professional tools will make it easier to get great results, under a wider range of situations, than you can get with modest, entry-level gear. Nobody in his or her right mind would shoot a night football game with an 18-55 f/3.5~5.6 kit lens if a better lens were available.