Can I leave comments for a point in time or range of time in the source clip? Also, is it possible to easily find the corresponding clip by searching based on that information?
Configurable on the edit page.
You can leave comments by selecting the clip of interest in the media pool of the edit page, displaying it in the source viewer, and placing a marker in that view.
But how do you hit the marker? I think there is also a question.
You can place a marker by moving the playhead in the source viewer to where you want the comment and selecting the shortcut 'M' or [Mark]-[Add Marker]-[Current Selection].
The keyword set here will be the "Search Target of Smart Bin".
It's convenient because you can leave the target range information in the clip at the same time as the keyword.
The information corresponding to "Shot & Scene" in "Metadata" on the "Media" page is not displayed in the file tab of the editor's inspector, so set a keyword instead and add it to the media pool on the edit page. You can use it to check from above.