All I can tell you about the paint is that it's water based, and when treated with abrasive polish, comes off on the polishing rag.
!!!!!!!!Solvent Paint is still very much in the Market Place, in fact if you visit any Paint Distributor in your area you will most certainly find they can assist you in either providing Hydro Base (water) or Solvent Base Paints with colour match for your vehicle.
There are now (since2006) stipulations on what type of product you can use on your vehicle, (the directive is to long to type here)but in essence if you claim it is for touch up or a classic vehicle you can still purchase Solvent paint.
As for the operation, you will note on purchase that all cans are marked "for professional use only" therefore you should request TD Sheets, for application use.
As Dave rightly suggests touching in is an art that is gained through time working with the product closely after serving a approx 4 year apprenticeship and learning the skill of Blending.
Depending if the colour is a Solid or Clear over Base will certainly be the test of your knowledge of painting, even at its best blending requires at least 50% of the area beyond the repair edge to be covered.
As for using an Air Brush what in fact you are looking for is 0.2mm needle set up which In my opinion is to small, you would be required to thin the Paint to much to allow it to pass the through the Gun, my advise is to purchase a 1.0mm or 0.8mm small gravity Gun, this will give you the flow you require but with some control and consequently allowing the correct amount of material to be applied.
It should also be noted that
TOUCH IN means the size of the eye of a needle, anything larger is a repair
Preparation is key, the finish will be easy if the prep is perfected.
Paint will not polish off if it is hardened (cured) fully, basecoat will require a Lacquer to protect it from weathering and external UV rays.