Usually storage rather than use. Pieces pressed against each other chip and scratch, and lofts get really hot in summer. Wrapping each one and storing somewhere temperature-stable makes the biggest difference.

Some are, some are not. It varies by product. A single-sided piece needs positioning so the printed face is outward, and it can turn if the tree is knocked.

Closer to the trunk, where branches are stiffer. Outer tips flex and a heavy ornament placed there will droop or slide, especially on an artificial tree.

Because lights sit immediately behind and around the ornament. Backlighting washes out low-contrast detail. Strong outlines and darker tones hold up far better under tree lights.

Not necessarily. Most households add a piece a year, so collections are deliberately mixed. Buying single items is normal in this category rather than unusual.

Here they are a feature. Ornaments are kept for decades and often mark a specific year or event, which is the opposite of how a dated design works on clothing.

Individually wrapped, not loose in one box, and stored somewhere that does not swing between extremes of temperature. That single habit prevents most of the damage people blame on quality.