I used to carry my knife strong side, then I got my CCW. Then I had to learn to draw my knife from my weak-side - but it is a must have. Tactically to fend someone off from grabbing my strong-side/weapon, and as an everyday tool.
Extra mags are nice to have, but if you empty a magazine in a gun fight - you have many more problems than not having more rounds... Get away man, save your life...
Agree 100%, carry what you know, not what is 'cool.'
Remember, the more you know, the less you need.