Is it possible to stay zoomed in whilst using either the angle tool to draw a straight line or manually adjust the rotation?
Or is the only way to crop for zoom, correct the angle and then uncrop (or copy the angle, click on the edit before the zoom-crop and then reapply the angle)?
Similarly, the method I've come up with to correct things when there are verticals but no horizontals is to do a 90 degree rotate (either CW or CCW), use the angle tool to align with one of the new horizontals and then do the inverse rotation. Is there a better method than that?