All you really need is a good lens and a good shutter, the rest is nice to haves' and convience but the most critical ingrediant is the dude behind the camera. He's the one who decides, shutter speed, depth of field, flash addition and composition composition composition...... unless you are operating in auto mode.
I am amazed at the number of people who buy really good gear and rarely use anything other than full auto to make happy snaps.
I used to chair a photographic society which included a sales outlet and we ran courses from the basics to advanced and produced some very competant photographers.
Being sponsored by a mine meant that we were rolling in funds and could invite top professionals up for weekend workshops. I also did 'sensititive' and other photo jobs for the mine on a commercial basis. That was in the not so good old days of film and slides.
These days I am getting lazy... too hard to get out of bed before first light unless I am somewhere really special.