That's based on the rules used for grand jury proceedings in your state. Grand jury proceedings are NOT trials and many of the protections given a defendant in a trial are not present in grand jury proceedings. The role of the grand jury is just to determine if there is probable cause to proceed with prosecution. Probable cause is not a very high standard to meet. In SD the same rules of evidence that apply to public trials and hearings apply to grand jury proceedings. However, my review of the rules of evidence does not expressly state that a witness must appear in person. SD case law (court decisions) may address that, but I've not looked into that. 

Nope. In a grand jury proceeding, neither the suspect nor his/her attorney are allowed to be present. The proceedings are held in secret and the people who can attend the grand jury's proceedings are extremely limited. When taking evidence, the prosecutor, witness, and court reporter are allowed to be present but no one else. There is no right of the suspect to cross-examine a witness in a grand jury proceeding and indeed the rules regarding who may be present during those proceedings would exclude the suspect and hi/her attorney from even being present. After the grand jury proceedings are concluded, the defense can get the record and file appropriate motions if there was any irregularity in the proceeding.