Seen and heard hundreds of them and I do not worry about them at all. They flee as soon as you are seen 95% of the time and the other 5% of then look at you for a minute and wonder off. If you live out west like I do they are of little concern.
Yes, that has been my experience as well.
Though in the extensive urban parks in my general area, it's worth noting that coyotes have not only made themselves at home but have lost essentially all fear of humans. Unlike rural areas, where they are still cautious/respectful for obvious reasons (blam!). I would not trust urban coyotes where a small child was involved; they are gifted opportunists, and have enormous talent for showing up the second your head is turned.
If you live in those few eastern area where Coywolves exist they may be a bigger concern. These are hybrid species of Wolves and Coyotes and may be more aggressive than a true Coyote. Even with this subspecies, you have little to be concerned about unless you physically run into it while on the trail.
Yes, these are much larger and apparently bolder than the coyotes I see. There was an extremely rare fatality a few years ago in Cape Breton IIRC, where two coyotes attacked and severely injured a lone hiker, who later died of her injuries. Memory is fuzzy, but as I recall the coyotes later shot by wildlife officers were around 100 lbs. each.