OY Andy . . .
IMHO 75% of the features on cameras are useless (or they may have a one time unique application, and you may never use it again).
Two suggestions . . .
Play with it, use all the stuff and see what you can do - you are smart enough and tech savvy to figure most of it out. After all, it takes no film to shoot away.
Do a google search for a camera forum about your camera.
You can already use it on auto, the basics you need is to understand aperture and shutter priority, the ISO speed you want to shoot at, and how to correctly use the flash and lighting.
The rest is for the most part, well, FLUFF.
Good luck - sorry I can't be more helpful, but I don't read the manuals much either, I have picked up my knowledge over the years and many cameras.
John1