Answer:
This is a tough one but I am a commercial photographer who works on Advertising and Editorial, magazine, work so
1- Often you try to create the work that you enjoy or says what you are trying to convey upon the viewer. Often over a period of time your "voice" becomes more clear and then you start to search out ways to use your medium to further show what it is you are saying to the audience.
2-It is constant. In advertising it often is focus groups that look at what has been done and then are asked to tell someone who does this for a living what they feel from the art. Often a number of multiple choice and associatinal type of questions are put forth by the mediator running the sample group.
3This has a lot to do with the medium of the artist . A painter would clean their brushes and make sure the bristles stay treated and don't become damage. In pgotograpohy we chare a rental fee for our gear we own as well as what we rent. That money is partly income but mainly it is so you can have the camera and lenses servided by a pro. You can purchase new flash bulbs to replace the ones that explode or break. This renta'; money is also saved to use for your business insureance and to upgrade cameras lenses etc. as technology advances so you can stay relevant and on the forfront of your craft.
Step-by-step explanation:
I hope that helps shed some light on your question