Hey OffWidth,
I'm certainly no expert, but that mix sounds about right to me...
Mine seem to do OK with approximately the same ratio and ingredients, although I substitute a volcanic rock sold here (UK) as cat litter for vermiculite/perlite. This is purely as it's a UK cacti-grower trick as it's not only fit for purpose, but cheap and available from a major supermarket too.
I tend toward holding back on watering for at least a few weeks when I first receive and pot a rooted cactus, but I'm told by other (much more experienced) growers on here that this isn't strictly necessary.
Other than that, a little bit of fertiliser (occasionally) and
pachanoi enjoy more water than I expected - don't go crazy though!
Hope that's of some use anyway! If no-one else chimes in to improve on my answer, remind me and I'll dig out some guides and other useful info I have on the subject...
Cheers!