Publisher’s aqua colored grid guides are about 2.5% as functional as PhotoShop; they disappear in the region occupied by the graphic. But I just learned for centering graphic objects, that if you have it selected, with a handle at 12 midnight, on a letter page 8 1/2 wide, you can manipulate the window up and down so the handle will center on the 4 1/4 ruler mark, then nudge left or right to center exactly.
I won’t say what compensation tactic I’m going to use, so they don’t come and stomp on me.