There are features that do precisely what you are looking to do, I think.
- Tagging text: there are two approaches, you can either put a mark in the text itself using an Inline Annotation (these can of course be stripped out when you compile). The advantage to using this method is that the tag is right in your text editor. Easy to spot, and easy to search for. The other method is Comments, which highlight the phrase in question, instead of sitting beside it, and the tag goes into a box in the right sidebar that you can hide. The advantages there are obvious, with the slight drawback that regular Cmd-F search won’t find the tags. It’s not a huge drawback though, because the Edit/Find/Find by Formatting… command can search by colour and text typed into the comment. This tool also works for inline annotations. You’ll find complete documentation on these features in the user manual PDF, in chapter 18, Annotations and Footnotes, including the format finder.
- Collections: these are your lists. There are two types of collections, general lists that you can add, remove and sort items within yourself, and secondly there are collections that are basically a saved project search, so that when you click on the tab that search is reloaded and run. The latter is what you want. You’ll find general documentation on Collections in §8.4, Using Collections, pg. 83, and specifically search collections in §8.4.3, Search Result Collection, pg. 87.
To find comments you’ll need to use the Text or All project search modes.