There are compatible batteries with slightly higher capacities, but they still look very unimpressive on paper. I'd be concerned about the cost of buying a spare and the likelihood of being able to find one if you were in a rush.

Worst. I've seen studies on this. The office is following people around wherever they go — as opposed to the promise of being free from the office. So not only are you at the office for eight hours, now you have chains linking you to the office the rest of the time.
Also, computers were supposed to take the humdrum out of work – do the boring, repetitive tasks for humans. Instead, studies have shown computers are used by employers more to monitor employee performance, to watch over what they do during the day and, ultimately, to increase the humdrum.

kind of a tough one, the fact that the graphic shows up leads me to believe that at least the buttons aren't broken and that it's a software issue. lets explore those possibilities:
1: there is a configuration where you can change the sensitivity of the buttons, where you can set it to go volume up quickly with just a couple of button presses, or very slowly with a lot of presses, like fine tuning volume. it's a very long shot, but worth a look.
2: the buttons might be shot, hold down the buttons for a long time (5 seconds) to see if anything changes.
3: uninstall and reinstall the program associated with the keyboard buttons. usually it's called DELL quickset or some other form of dell software, if you've accidentally uninstalled it and can't find it on the original disks without reformatting, then try the dell website and search for software and driver downloads, use your service tag on the back of the laptop to find the right software. As a matter of fact, this might be the first thing you want to try.