Some capability lists are unbelievably unclear about the annular ring. It’s possible that a larger value, 0.2mm or 8mil, is “very safe”. That would make the via copper diameter 0.8mm or 32mil. But most can handle 0.15mm/6mil ring anyways.
Pretty safe minimum copper to CNC routed board edge seems to be 0.3mm or 12mil. Copper to V-score line’s center 0.5mm or 20mil.
Less critical are legend (silk screen) text sizes: character height 0.8mm, line width 0.15mm. That should be small enough with 0603 components and “very safe” clearance values which give room for the text. Manufacturers will probably let you try smaller without extra charge, you will just suffer if you can’t read the text. I have seen 0.6mm/0.12mm being so and so but usually readable even when the recommendation was 0.8/0.15.
Then there are the solder mask values: minimum bridge or dam or web (=“minimum width” in KiCad), and the solder mask pad clearance. You don’t have to care so much about them before deciding the manufacturer because in KiCad they can be set globally if needed. Often the manufacturer doesn’t even give values. They may decide the best values which suit their processes. Bigger values aren’t better, see Filled zone cuts corner of mask on square pads for some problematics. Some common values which are given are 0.05mm and 0.1mm, the latter may be said to be safe. Expected value for minimum width is also 0.1mm.