the things you are saying are the same exact fears held by people against the irish, italians, jews, blacks, chinese and other such groups at one point or another in history.
america today is the result of different cultures. there have always been people like you who throw up a big fit but in the end the new infusion of other cultures often yields positive results. or at the very least it never destroys an entire culture and replaces it outright.
that just doesn't happen. all cultures shift over time. as i've said america has changed more in the last 230 years due to technologies rather than immigration.

Bow ties are coool.