Everything. The adaptations your body has learned to fight other diseases are stored as T-cells. When you need more of that particular kind of thing, your body goes and runs off copies. Measles kills your T-cells, so your body can’t copy the old adaptations, only make blank-slate factory-new ones.

Any Markdown editor, yes. But not everyone is familiar with Markdown formatting. People coming from text editors, forums, and word processors expect a single enter to start a new paragraph.

Keep it? I think Bi is the big umbrella which contains pan, omni and poly/multi.

Pan seems to be gender blind, i.e. attracted to people with no regard to gender or attracted to all genders.

Bi has one definition in being attracted to both men and women, both sides of a binary.

Bi also has a less common usage to mean attracted to more than one gender which may or may not include both halves of the binary or the entire spectrum.