Logic Pro for Mac: "Remove Silence" window - Interface shortcuts, preview zoom, and what is "Search Zero Crossings"?

I have some questions about the Remove Silence window in Logic Pro 11.2.2:

1 - What does the "Search Zero Crossings" option actually mean? From the Logic Pro manual:

"Search Zero Crossings: Select this checkbox to automatically snap the region start and end points to the nearest waveform zero crossings.".

What does this mean? Does it mean that it moves around the position (timing) of the cut-out audio parts by snapping them to something, so vocals might accidentally get out of sync? What even is a "waveform zero crossing"? When should I have this setting enabled, and when should I have this setting disabled?

2 - I'm not really good with remembering keyboard shortcuts, even though the shortcut for this one is pretty simple (CTRL X), but is there no way to click a button to easily access this window? Clicking on "Help" and searching through the macOS menu bar items for Logic Pro doesn't bring this option up when searching for "Remove Silence"?

3 - If I have a really long audio region that I'm applying this to, is there really no way to zoom in on the preview in the Remove Silence window? I know many podcasters use this tool to cut out silence on 1+ hour long recordings, but it seems really hard to view the difference between different milliseconds settings when changing the parameters in the window, when a 1+ hour long audio region tries to fit into a few centimeters of screen real estate. I know I can cut out a small portion of the audio region to experiment, try some settings, screenshot the settings I decide on, join together the audio regions again, and then apply the settings from the screenshot, but that doesn't seem very intuitive...