If we're discussing legal immigration, I suppose not- however, it ought to be taken into consideration.
Well, if I'm not mistaken even illegals have access to education and healthcare in the US. I'd say that realistically one has to take into account that immigrants in general (legal or not) will need access to healthcare and education, and that it's not advisable (if not outright stupid) to deny them so.
Also, by legal immigration you mean foreigners who get permits for permanent residence? If so, they get access to the whole safety net I think.
As far as Ghettos are concerned- the represent a multigenerational problem. Education might be a good move, but would barely mitigate further immigration, let alone full deghettoization.
Hmmm, in the long run I'd expect immigration to stop. Why would a well-off person move to another country which (s)he doesn't identify with/want to be part of? Usually, these people stay temporarily for economic/political reasons and I'd expect exceptions to this rule of thumb to be... Well, exceptions.