I think a User Tool (perhaps in conjunction with highlighting a text) is probably the way to go, but another option is Reference Lists. Given that you are thinking about 100 topics, that might get unwieldy, as you would probably want to save each Reference List as a separate "tab"/document.
Reference lists let you collect verse references in a tab and then display them in whatever translation you like. I mostly use them for temporary tasks. For example, I often base the greeting/call to worship on a psalm or other poetic text that has thematic connections to the main preaching text. I use the cross references tool to search for possibilities, and store likely candidates in a Reference List tab.
But I have occasionally use Reference Lists for more permanent lists/tasks. Just make sure you save the Reference List after you make changes in it. Unlike User Tools, this does not happen automatically. (Another reason why User Tools are probably a better option)