Is 22 gallon air compressor fine to pain small stuff like car fenders and bumpers.?

you can paint with it, the unit has decent pressure and flow rate

as for the results, it depends on the spray gun used, the paint quality, the skill of the painter

Way much more than what is needed. I can paint a whole car with a 1 1/2hp 5 gallon tank dual head compressor on the the size of Chevy Impala 1969 4 door, or a VW panel van, or a Mack truck.  You only do one vehicle at a time.   You drain the tank after to get the water out.

You are only spraying at 40PSI or what the paint can recommends for the paint you are using.

Watch YouTube video's to get some idea of how to do it.   My dad is a painter so my instruction came from someone who does this.

 5 ponies is generally considered the minimum for running paint guns especially HVLP units. I have a few C.A. Technologies  guns and a few no name big bore units for primer. I can panel paint down to 3HP. I regulate the HVLP guns at the gun not the compressor, that way you can get by with standard A or M fittings and not have to change every air tool you have

Yes.

With the proper other equipment. 

Consider an air line dryer. 

Water in a paint spraying operation makes problems.  

I used a 2 stage regulator, so the line pressure is rock stable for the paint gun.

yeah dont forget the air/ water filter and stuff. practice on cardboard so you can adjust the spray gun and whatnot.

Sure that will be just fine