HaLeivi: Kind of. Not always is saying it outside the context of the Torah removing its holiness. For example, “ani l’dodi” has a meaning kpshuto shel mikra as well, and in the context of one’s wife it is a holy statement which has adorned k’subos for centuries before it became fashionable to put it on jewelry.
klach: Regarding your second point, the gemara quotes partial pesukim all the time, as do all rishonim and acharonim.