Powerful manager of default applications?

I don't believe there is one app to do what you want, but a combination of the following should do it.

RCDefaultApp is the old stalwart of extension/mime/creator code and many other types of mappings. In the transition days between Mac OS 9 and X, I used this extensively to deal with all of my files with Type and Creator Codes.

For more complicated file opening control try Magic Launch which can select the app to use based on currently open apps, file path, file contents, tags, etc.

This still doesn't give you control based on URL. For web addresses try Choosy, which gives a nice interface to select the browser at time of clicking on a link or via automatic rules based on strings, regex, and more.

Note: I don't currently use any of the above. For selecting which app to open a file, I use LaunchBar's ability to specify which app to open a selected file.