"Brass prep: What steps do you feel are a waste of time?"
That's a loaded question (intentional pun). The only way I can pretend my reloading hobby is cost effective is by totally ignoring the time I spend doing it! It's a hobby, and I do it for fun. Until the zombies show up, I don't really "have" to reload at all, I choose to spend the time doing it. I know it seems pedantic to make the point, but by replying at all to such a question is pretty disrespectful to the crowd that choose to take additional steps for their own pursuit of th'hobby.
Steps I choose to not spend time, money or much thought on (but respect those that do) after decades planning, and a full year of "doing" with my own equipment?
-Tumbling brass. I inspect the cases I use/re-use, and wipe off anything that may affect a die. I do brush inside. I have washed a bucket-full of "gifted" brass that was covered in some miracle mud that didn't wipe off, but I really don't care about aesthetics of the brass in general. Function over form.
...green patches excepted, I'll abrade/rub that off to be certain it's smooth.
-Primer pockets...same as general brass stuff. I inspect after de-cap/ resize, but unless the flashhole looks odd, or the grime very serious, they get passed. I have handtools to do cleaning, etc right in front of me, but only touch 'em as required.
-Neck-turning/checking runout, etc...so far my purposes are well served without any consideration of this. I do reaaaaaaaaaalllllllllllly look forward to the day when my own results might be affected by miniscule detail.