Is Boom Operator a highly desired job in the US Air Force?

Yes, it and loadmaster are two of the main air crew jobs available to enlisted. JP321 gave you the best information.

yes, all enlisted air crew jobs are highly sought after

if you get the AFSC,training starts immediangly after basic, and takes a couple of months,

then after you get to your first base, on the job training takes 6 months to a year

I've worked with a good number of boom operators. Some guys would call them in flight gas stations attendants, but you really have to have some steady hands to do the job.

You have to be at least 5 feet 4 inches. It's not hard to do the job, so a lot of people apply. I don't know how long it takes after BMT, but you're talking about something that is not highly technical. Average to less.

Funny story. We once had a guy who couldn't stop drinking They would not discipline him either. He had connections. This guy's hands were so shaky that he ended up being really sloppy. He finally got chaptered out and ended up pumping gas at a car gas station in New Jersey (where apparently it's illegal to pump your own gas).