That I can't imagine. Among the natural rights that an indivudual has is the right to exchange his property at will. If he wishes to exchange property with a non-citizen, the govenrment's job is to assist in the transaction, not to ban it.
I can well imagine that a government would limit land ownership to citizens, as an extension of the idea of defense of the nation. We might want to limit immigration and communications electromagnetic spectrum (radio and t.v. channels) based on the same idea.
Another reason: ease of ability to apply the court system of the nation to citizens, as opposed to foreign holders.
Yes, I agree with that. As long as there is a credible concrete threat, the government may restrict trade in some specific circumstances. For example, striking a private deal with some Arabs involving weapon sales would be rightly prohibited under the circumstances. Those are temporary wartime restrictions.
I don't see facilitating the government in applying legislation is enough justification though.