Not all legal immigration is good ---not when some come over, have an illegitimate baby they plan to use to collect welfare and gain citizenship through that route. An illegal not committing fraud and working hard for cash, learning English and our customs might be a better citizen than many who find loopholes in our laws and get right on welfare. Many living in the projects here technically became legal (usually by having babies at the county hospital) but aren't here to work.
I agree that the character of the individual will ultimately decide the quality of citizen that a person becomes, and that legal immigrants that come here to exploit any loopholes in welfare and social services are not good choices. I don't know exact statistics, but I suspect that they are a small minority among immigrants that choose the legal route, however.
Also, I agree that there should never be more than 5 or 10% total foreign born immigrants in this country at any one time ... we are fragmenting and balkanizing our country every day, so numbers have to be controlled to allow for assimilation and accomodation.
Under no circumstances should illegals be rewarded with amnesty. In fact, I am all for ammending the constitution such that persons born in this country to illegal aliens do not automatically become citizens. And if you are caught as an illegal alien, you can never come back. Period.