Any horoscope could be filled with tens of thousands of asteroids-- there are literally that many that have been mapped to date. Although I use asteroids occasionally, normally I wouldn't consider asteroid-to-asteroid aspects because it's just too easy to fill up a chart with so much space junk. I think an asteroid-planet conjunction gives the planet a bit more interpretive information.
Chiron has a lot of meaning, regardless. It's an odd little heavenly body, having some properties of an asteroid and some properties of a comet. I think it has real meaning in a chart interpretation, but I'm less convinced about the remote centaurs.
I would suggest you first get a good grasp of your chart based on the major planets and aspects.
If you want to go further with minor heavenly bodies, first get clear on their individual core lmeanings. Then think of areas of overlap in interpretation with a conjunction because these two bodies are "joined at the hip."
But please take Nessus with a grain of salt. It's been called the asteroid of "devient sexuality" and abuse, which can't possibly be true, because everyone has Nessus somewhere.