I was just thinking of airbrushing myself...if you used a fairly liquid-y dye or paint, airbrushing it on probably wouldn't affect the texture. I've never really worked with an airbrush before, though, so take that all with a grain of salt.
I agree with Katxena that you've probably already fixed your laddering problem and it won't happen next time. However, for this hat it would probably help to block it, especially since it's wool. Natural fibers are pretty responsive to blocking and while the wool is wet you can kind of "sculpt" it into better shape. Sometimes if I have a looser piece of stitching, I will also use a crochet hook to pull that stitch tight, then just kind of keep following the yarn back, distributing the extra slack throughout the rest of the piece. I don't know if that makes sense or not.
Wow, can I live with you?! Seriously, though, I love what you've done with the apartment. I, too, am a big fan of cowgirls, pinups, etc. and love the bedroom just as much as the cherry blossoms. I might have to add cherry blossoms to my bedroom walls...
Interesting discussion and lots of good suggestions. I work in a lab, too, with HIV and most of our sanitizing (outside of using the autoclave) is done with either UV or alcohol. The UV would certainly be easy to use if you can gain access to a source. The alcohol is an easier at-home option. We use a solution of 70% ethanol in the lab, but most sanitizing hand wipes and hand sanitizers are also alcohol based. The alcohol is unlikely to hurt the yarn, but it's definitely a good idea to test some extra yarn first.
I also think that it's an awesome friend who not only knits a beautiful gift, but then worries about making it safe for her friend!
For the crook (shepherdess cane), you could use a broomstick as the base, bend a piece of coat hanger for the upper curve, then wrap the top in duct tape. You could use rolled up paper towels or newspaper to add some thickness to the coat hanger before wrapping so you don't have to do a hundred layers of duct tape to make it look right. Then I'd probably cover the broomstick and coat hanger with a final wrap of tape (maybe brown packing tape, so it doesn't look so duct-tapey).
Hmmm. I'm not sure how you're ending up with an increase at the end of that sequence. In theory, as the post said, you should just be converting three stitches into a different three stitches, so you'd end up with the same number. Getting your right needle into all three stitches and then pulling loops through can be pretty awkward for this part, so I found it helpful to keep the first knit in the front loop a little loose so I could swing around and knit through the back loops and then through the front again. Make sure that for each of those three knits that you're getting your right needle through all three of the stitches on your left needle. That's all I can think of. Hope it helps!