The 3.8 code for Fabrik is now available on github, in the 'master' branch. If you are familiar with updating Fabrik from github, we would appreciate it if you could test this code on J! 3.8 for us. Once we have some feedback, we'll build a 3.8 release.
Remove a list column
In components/com_fabrik/views/list/tmpl/yourtemplate/default_headings.php, you have a variablePHP:$this->headings.
This variable is an array, which is keyed on the full element name and whose values contains the headings for the list