Any actual vocal instructors or people with real training...?

I wouldn't consider it overly nasally. Maybe a little more nasally than average, but so is Barbra Streisand's voice and no one complains about her. If you wanted it to be more chesty you could do vocal exercises geared towards increasing power in the lower range and bringing it up to the higher range. But overall, I think you have a lovely voice that does lean towards higher soprano songs and you've done a great job of choosing songs that cater to that.