Those are custom shortcuts he shows and you can add them, too.
I would advise against using X for a keyboard shortcut, at least if you aren’t using an extended keyboard. By default, X is set up for linear and radial arrays. * also works but requires the Shift key if you don’t have the number pad.
I have Shift-I for Paste in Place but I would have designated that myself because more obvious keys are in use for more important things. I would guess you can do anything on a Mac in this respect as you can in Windows. My Mac doesn’t slow me down.
I set ctrl-v as paste in place on my Mac because cmd-v is regular paste instead of ctrl-v used on Windows. Not much mental bandwidth needed to remember it
Downloading realistic seamless textures increases the realism of your model. I like textures.com. Also, Twilight render V2 is an easy-to-learn free renderer for adding lights, reflections, and bumps to surfaces.