We are always taught "Get it right in the camera" and as far as exposure is concerned, I could not agree more. In the days of film, post production was slow and difficult but in the digital world, with big improvement in Lightroom and CS6,...
I was also taught the same way as you were: most of my industrial and scientific photography at work was in Kodachrome. We'd take some bracketed shots, send it to be developed, get the slides, load them into the carousel, and go do our presentations. So exposure was critical.
Slides have been replaced with Powerpoint. Now with CS6 and the huge dynamic range of my camera at ISO 100, I find myself less concerned about coming up with compromise exposures for the whole scene: I expose for the critical portion of my photograph (say a bright computer monitor or a dark area with a key feature in it, and I used masks and exposure compensation to fix the rest in post. It takes almost no time and gives great results.
I do the same as you with white balance. I usually stick a small gray card in a place I know I will be cropping out.
I had an interesting case this weekend. Because of restricted access, I couldn't get a lot of shots from a lot of angles, so I took one shot with a wide angle lens.
Afterwards I found I needed to make some text in the foreground of a photo I had taken pop out more, even though I had focused for the main part of the subject. There was some important safety warnings that I wanted to be in focus that I hadn't originally planned to use, but with a little bit of sharpening and I could crop right down to the text. Similarly, I wanted to draw attention to a black knurled nut on a black anodized aluminum housing. I masked the housing, brought up the exposure, and cropped in to the feature. The high resolution and high dynamic range of the camera really worked for me.
I am getting lots of mileage out of one photograph instead of many by crops, exposure compensation, and sharpening. I know my work is not art: it is purely functional photography, but I am getting paid and the amount of time I am spending on the photographic part of my job has gone down enough that I can goof off on NRF.
I don't use jpeg in camera any more. I convert to adobe raw and go from there. I save the files in jpeg for the client, though.