Legal Question in Civil Litigation in Illinois

Re: Identification of proper party plaintiff

Yes. Courts do not require plaintiffs to be citizens.

The fact that you have been denied entry to the U.S. creates logistical problems but no legal ones. At some future date in your lawsuit, you may be required to appear in court, or at a deposition in the locale of your filing, but competent counsel should be able to have the court set aside these requirements if they arise (and depositions can be conducted telephonically with leave of court).

Re: Identification of proper party plaintiff

Yes. Generally, any natural person can be a plaintiff by submitting themselves and their dispute to the jurisdiction of the court. You would simply hire an appropriate lawyer, licensed to practice before the court, to present your claim to the court.