A probably unpopular opinion of mine is I really like the idea of kyber crystals changing colour depending on what emotions you channel into them. The concept of ‘bleeding’ a crystal with negative emotions, turning it red (and the reverse, ‘healing’ it to turn it white), was introduced in E.K. Johnston’s Ahsoka novel and I’ve seen it get a lot of flak. I think it’s a really nice artistic touch though and a great in-universe explanation of the different lightsaber colours.
Not so sure about crystals being alive, but I certainly like the concept of them reflecting the emotions of their wielder - in the same way as Jedi/sith force techniques like lightning.