Looks like it's been traveling in some dust ...I like it so far
Yes you can do washes with an airbrush....you could use either of the airbrush tips you have....you can do a overall spraying (big tip about 12 in or further) with highly diluted color and let the pigments settle to where you like....or you can do a fine line with the fine tip (close...real close to the surface you are addressing) and diluted color and chase all the lines bolts etc
No real pros and cons to it...it just takes a little time and practice (Trigger control is important ) to get the effect you want

I have other tricks...but I've found it isn't too good to be open with those things lol ...so try this first ...if you don't get the result you want...I can tell you a little more in a PM
ALPHA