Again I am not sure how important find and search/replace is for most dynalist users I originally posted this request. And it still is very important to me. "Search" to me is not just a one to many relationship but a many to many relationship. I use dynalist as scheduling tool. (and I like it very much) Context (what, who, where, supportref, etc) and status (nextaction, recap, rewrite, etc) becomes very important in documenting, doing, and filing) and can only be accomplished (IMO) by tags and (better yet) nesting tags.
To that point i have found a somewhat type of workaround. Documents are my projects. Bring up a document. In win (ctrl a) and copy all document items and paste into a new note in evernote.
from there use evenote: Edit>Find & Replace>Replace within note. Follow dialog prompts and one can find and then replace all tags that must change. Once changed one can then recopy back to dynalist.
A bit cumbersome but works. (note!) could not get this to work for gdocs on a pc. hope this helps those with similar challenges as mine