> launching a terminal at a location
Right-click on directory > Services > New Terminal at Folder.
> viewing or copying a files path
Right-click on directory or file and press Option > Copy "<filename>" as path name.
> navigating a deep file system
Not sure what you mean.
> column width in the column view
Option + click & Drag. Or do you want them to adjust to files/folders name length?
> searching for files
What's wrong with Command + F?
> finding file info
Do you want more than what is shown by Command + I or in the "details" column?