I don't like telling people to hand-edit .idlerc files. It causes too many problems.  We added Extensions tab to avoid this.  I think all supported options should be on dialog.

Windows are resizable and accommodate lines up to current width.  Default width is user settable option.  So people who want to edit 100 char lines for code can and have editor open with 100 char width.

Shell,Edit, and Output windows should not necessarily be same.  Currently, Shell wraps both input and output while Editor Output truncate code input and grep output respectively.  I plan to review this, including possible scrollbar, but not a priority.