Regarding browsing remote files in the SVN Repositories view, I noticed the Subclipse provider only supports an "Open" item in its context menu. Thus, a remote file can only be opened according to Eclipse's File Associations or, in the event of an unknown extension, the launching of the native OS shell dialog to choose an external program.
I am requesting an enhancement to add an "Open With" item as seen elsewhere in Eclipse. It should be possible to examine the remote extension and provide a list of compatible editors. The association doesn't have to stick -- it could just be a one-time operation -- and that would be good enough for every day purposes.
I believe the Subversive editor, for example, does something similar already.