I generally prefer a scientific (or pseudo-scientific or 'rubber science') explanation for this--and pretty much everything else of a 'supernatural' sort. My peeks into the future are more akin to what one might find in Dune or The Book of the New Sun. I suppose one might argue that, at its...
It is. OpenOffice doesn't keep adding as many 'bells and whistles' and might be a tad more stable. I use Libre mostly because it comes with most Linux distributions and implements more OpenType features. I need my small caps.
Being old-fashioned (or maybe just old) I do all my writing off-line, mostly using LibreOffice. Drafting on my laptop, comfortably on the couch, editing, formatting, and all the rest at my desktop in the office. Frequent back-ups via equally old-fashioned USB sticks. If you do need others to see...
Wrote quite a few when I was younger but they were mostly for fitness and bodybuilding magazines. The world has changed a lot since I was sending typewritten pages to editors.
Once I have a map I generally take the attitude 'this is your world, deal with it,' and build the narrative to match it. Just as I would when writing historical fiction. If nothing else, it makes it easier to move on with the story.
One could always have an adopted human who thinks he's a dwarf, like Carrot Ironfoundersson in the Discworld novels. And Moorcock had a 'dwarf giant' (i.e. giant with dwarfism) in one of the tales.
I finally chose to ignore piracy of my books altogether and followed Cory Doctorow's example of giving away the ebooks. If nothing else, it simplified my life.
Actual 'little people' --- sprites and brownies and such -- have only shown up in my children's books and I went with the conventional choice of naming them for flowers and that sort of thing. Marjoram the sprite, Hob and Gob the brownies. Nettle and Nightshade the goblins. And so on. The elves...