That copy stick looks like a great way of getting the parallel fence to be perfect with the flip stop!
I typically only use it when i'm trying to get a super nice cut on a full length of plywood for a gable or something. In those cases, i can get a parallel cut that is as far as i can tell reading a tape measure, exactly parallel. If i'm less than .5 of a millimeter over an 8 foot length, i'm happy. I normally only do this type of rip cut on the front edge of a gable end or something. The other edge will be scribed to the wall and the bottom edge scribed to the floor.
As for toe out on my slider, I have no idea what it actually is. I'd have to measure as you have with a dial indicator, however i would assume it's less than 4 thou. The same could be said for my rip fence. 4 thou out over 8-10 inches would have it out by roughly half a millimeter for a 4' cut and i'm definitely less than that.?With that said, you will never see my saw with a regular blade in it and no riving knife, so kickback from contact with the back of the blade is pretty much a non starter. Not that it doesn't happen, but the chances are dramatically reduced.
We all learn what we know from different sources and i'm just passing along what i have learnt from some amazing old tradesmen that i apprenticed under, and others that i have learnt from over the years as a wood machinist. One of the great things about a trade is that there's always more to learn if you're open to it. Actually that's something that is different today than it was 30 or more years ago. Back then, (at least in Australia) you would do your 4 or 5 years as an apprentice, then once you were finally done, you became a 1st year tradesman, then 2nd year tradesman, maybe even a 3rd year tradesman. After that, the old timers would let you be, but until that time, they would make sure you knew you were basically only just out of primary school, and into high school, and you definitely had lots more to learn! :) That's one of the great things about this forum, there's always little bits and pieces you can learn from some very passionate woodworkers.
Regards,
Bryce
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https://www.brycecomerwoodworks.com/
https://www.youtube.com/channel/UCHdrRaAZd_pOa7wwbdNPUEw
Bryce Comer