Modeling tolerance question for inserts, hardware, hinges, etc.?

[curious aardvark]

edges shouldn't be sharp. A set of small files and sanding blocks also comes in handy.
You should find that if you print stuff at 0.2mm layer height, tolearances are pretty good.

First time I made a threaded part I was surprised at just how much difference there was in the bolt thread and hole. It does depend on the size of the thread - but I think I was making the bolts around 30% smaller than the threaded hole for a smallish clamp.

Every machine and filament combination is different.
So you'll just have to print some stuff and then work out if you need to adjust anything.
3d printing is currently as much an art as a science and every 'machine-operator-workshop-filament-print surface' combination is unique.
What works for me may not work for you and vice versa.