lol, don't worry about it. Those
pipe cutters I refer to are pretty much idiot-proof ;-) Just screw it down until the cutter makes contact and run it around the tube a couple times, tighten down the screw a tiny bit and go around another turn or two. Repeat until cut through. You can get a cheap one from Home Depot for less than $15
As for honing down the edges, you'd want to do this so you don't cut up your o-rings when putting the caps on or cut yourself while handling it. Any round honing stone or round/half-round file should work just fine.
If you do happen to find a good source for the right size SS tubing, be sure to share. I know others are interested in SS tanks. Myself, I'm fine with the plastic 'cos I like to see my
juice level