To view and save the tag info to a text file from a GUI, use ' mkvinfo GUI' from the Start menu. Don't forget to do a save on the file after editing.
Open your mkv file in the header editor and you can view/edit most if not all tags directly. Open Header Editor from the File menu (or ctrl-e). Launch ' mkvmerge GUI' from the Start menu. =P Still better than remuxing everything. Until then I'll just be a hunt & peck CLI monkey. It would really benefit the format to have an extensive yet easy to use tag editor. Unfortunately I don't have the skill-set to accomplish this task myself, but hope someone will in the future. Then you could set up filters and regex to extrapolate titles from the file names and even set auto numbering sequences for episodes and seasons, etc. What I am looking for is a front-end to this tool that would allow batch processing so you could format an entire series of files in one go. It's very quick and allows you to edit most any property, but is command line driven and cumbersome for me at least. It is easy enough for single titles using the tool supplied with MKVToolNix called mkvpropedit.