I actually think James Horner's score for Titanic is pretty good. It just didn't need the love theme twisting into a Celine Dion power ballad, anymore than Schindler's List needed John Williams's magnificent score shoehorned into a power ballad. ("My List Will Go On" is a nightmare I once had. I woke in a cold sweat.)
And yes, Celine Dion records in general would get a minus score on the bandstand rating, as far as I'm concerned (especially that ghastly Streisand duet Tell Him That The Sun Shines Out Of His Arse, or whatever it's called).
I suppose I'd better have a listen to the tracks you chosen here...