No. When a map is created from a template, that map copies the current template settings. It has no connection back to the original template, and changing the template will not affect any maps created from it.

If you have added new things to a template you wish to bring into an existing map, you can make a new blank map from that template, then in your existing map, use Draw -> Insert file, pick the blank map you just created, but once you have it on the cursor ready to place, just hit escape instead of going through placing it. This is enough to copy in all definitions to the map, including symbol definitions, fill styles and line styles. Note that it doesn't update existing definitions, it just copies new ones.

If you insert an fcw file into another using Draw -> Insert File, the line styles (along with fill styles and symbol definitions) will be copied over. Basically same trick as for copying over missing fill styles.

Keep in mind that line styles, just as fill styles, are on a per-map basis. It is not something that gets installed globally. This means that if you see a random option in the line style dialog or not, depends on if the template you started that had from had such a line style. It is not dependent on installing any particular annual or other product. These installations will never change anything in existing maps regarding line styles.

I have files from the CC2 era with this line style in them. (Check @Tutorials\UserManual\Selection.FCW)

It is a limitation of the Wizard. If you use the pre-defined template option instead of decide settings myself, you can just pick the symbol catalog template and it will use it without you requiring to save the file as a fcw first.

When you hit save from the first time then, you can pick the symbol catalog type directly.

No, there isn't any way of exporting the functional links, the index only becomes a text reference on export. Remember that CC3+ really just support exporting to image formats, and none of those have any support for interactive elements themselves.

I guess it would be possible to export the hyperlinks as some sort of list of coordinates if someone felt up for creating an XP module for doing that, don't think that would be really hard, but again, that couldn't be used just as it was, it would need to be imported into some other program that supported interactivity.