You can paint, draw, sculpt…create whatever you want to…within the boundaries of “legal” (as in not violating copyright, patent, and trademark laws); you can blatantly applaud, revere, criticize or condemn some socio-political, cultural, religious, or ideological status quo, icon, or idea.  Or you can just paint, draw, or sculpt something aesthetically pleasing.  It doesn’t matter the content except that your art pleases you.  However, when it comes to the point of interacting with people, good manners, grace, and gentility are required. 

You can be all the brat, all the revolutionary, all the snobbish, and/or all the haughty you want in private and in your art.  But, for the sake of respecting yourself and your fellow human, please remember that treating others gently and with consideration will win you more accolades than anything else.  It will also gain you favor, and, perhaps, sales along with it, from your audience.

If someone voices an opinion of your work, good or bad, thank them.  If someone derides you rudely, you have the option of ignoring them rather than striking back.  If someone favors you with a sale, remember them, and always thank them, treating them with the same honor and respect they did you in admiring and valuing your work enough to wish it a part of their lives.