Your witness needs to let you know during the cross-examination that you can safely raise a matter with them during your re-examination. Even so, whether or not you re-examine requires you to assess the state of your case.
Some aspects of questioning, such as having a witness declared hostile/adverse/unfavourable, or raising bad character, or attacking credibility require the prior leave of the judicial officer. Be prepared by having your script in your trial note book.
Closing argument admires the decision maker who has already decided in your favour and hopes to persuade the undecided decision maker to prefer your case to your opponent's. If you made promises at the beginning of the hearing then show how they were kept. If they weren't kept then have a decent explanation. Keep within the attention span of your audience, and deliver in such a manner that they can absorb and consider your points. With a judge alone be sure to inquire on the record as to whether you have addressed everything they expected.