These are some things I use my external editor (EditPlus) for that would be nice in UE. Let me know if I need to elaborate on any of them.
- Copy and Paste columns
- Find & Replace within a Selection
- Single keystroke to duplicate the current line
- Set up customized macros to execute with single keytroke
- Set and goto markers (set markers on lines of code that you can jump back to)
- Sort Selection (I may have 20 variables declared, and I can highlight and sort)
- Change all tabs to spaces (I like to work with tabs, but I have to convert them to spaces before I check it in our source control)