Why? You will have one PCB with more options to meet different customers needs.
Why? It’s going to save you a lot of time and minimise mistakes in BOMs
Why? This way, you may quickly damage all your prototypes. First, figure out what’s wrong.
Why? That is the moment when solder has melted down.
Why? Recommended land patterns are different. You may also want to use different 3D model for capacitors and different for resistors.
Why? Easier for documentation, easier for enclosure design.
Why? You can then very simply select elements (pins, tracks, polygons, ...) which belong to a particular net class. It’s very useful during layout.
Why? It’s the safe way to do it.
Why? It’s the professional way to do it. Many people read and use the page numbers – a lot.
Why? Most erratas are not important, but there are always a few which may cause you problems.
Why? Long crystal tracks may prevent the crystal from oscillating – so, crystal may not work.
Why? This will save you a lot of time and minimize possible mistakes which could happen when re-drawing the schematic.
Why? It speeds up development process. It may be time consuming to start developing software from scratch, especially if you do not have to.
Why? This is one of the most common mistakes done during creating a new footprint. It is very hard to fix on already made board.
Why? Find your files quickly, find your colleagues files quickly, backup the important files, know what files were used for manufacturing