I'm afraid that the ends breaking off nuts are what often happens when the nut isn't filled down to at least be level with the top of the strings. the two end sections of the nut are relatively thin and the higher they are, the more leverage on the base when the top gets knocked or caught.

I'd hoped that in the first two cases there might be enough of the ends left to simply file down the top of the nut, but there really isn't enough height left to do that. Definitely replace them.

The Fender is tricky. CA and baking soda is probably the best method to use here. I can't see an easy way to remove the nut without risking damaging the end of the fretboard or the binding. Even sawing down the middle of the nut isn't going to do any good, as you can't saw the whole depth because of the binding, so you'll only break the top part of the nut off, making it impossible to remove the bottom part.

You may be able to wiggle it lightly backwards and forwards with pliers, but if it's stuck in well, then I can't see it coming loose unless you use enough force to risk splitting the headstock end of the board.

Using a really thin sharp knife you may be able to fee the binding at the sides back to the 1st fret on one side, leaving enough room to tap the nut from the other side and hopefully shift it slightly so you can then remove it vertically. But you'd have to tap just the top part/end of the nut, which just risks it breaking off and setting things back even more. If you could do it, you'd stick the binding back with acetone and maybe touch up with some poly or a couple of wipes of TruOil or similar.

A hot hair dryer might soften the glue enough to just pull it out upwards with pliers, but there's always the risk of finish or other glued areas becoming unstuck and it depends on what glue they've used.

So try the CA and baking soda trick, and don't forget to mask off the board either side. I normally tape up the front and rear sides of the nut as well, to form a well that the CA can't escape from, so it goes right up to the front face of the nut. Is the Coronado nut plastic or bone?