Similarly - this is an area that has generally driven me a bit nuts for a long time 
... I don't really use Ctrl+Backspace or Delete ever, but ALWAYS use Ctr+Left/Right arrows to move between filename or text field entries in various dialogs. There's a fair bit of inconsistency in what each part of Opus considers to be a delimiter that the Ctrl+accelerator keys (probably wrong word for this) will move between.
For instance, a dash or underscore in the string (without-any-spaces-between-parts) is handled differently in terms of where the cursor ends up being positioned depending on inline rename, vs in the location/path field, vs {dlg} type dialogs, vs Confirm File Replace and Copy As dialogs. Hardly the worst issue to deal with, but a real wreckage of something that for me is fairly ingrained muscle memory.