My old teachers would say it is always incorrect to blend or ellide sounds, as proper talk must always be articulated. But daily speech blends and ellides many sounds, depending on the regional accents, so I wouldn't say it's incorrect; only kind of colloquial. In formal speech, it is preferred to pronounce and articulate each sound.
Here, in Mexico, it's very common to hear things like:
- Ps/pus/pos -> pues
- ¿Sa's qué? -> ¿sabes qué?
- ¿Ve'á/ver'á/vrá? -> ¿verdad?
- ¿Comstás? -> ¿cómo estás?
- A'i -> Ahí
Don't worry about pronouncing each sound; you will not necessarily sound artificial, but maybe just educated. However, if you can follow and imitate the way the people on your CD speak, you will manage to acquire a more fluid accent to talk in different registers.