Of course now that I finally decide to post the questions, one of the answers reveals itself.
To set the default rows and columns for texteara elements, go to
lib/form/editor.php
Look inside the function toHtml();
$rows = empty($this->_attributes['rows']) ? 5 : $this->_attributes['rows'];
$cols = empty($this->_attributes['cols']) ? 80 : $this->_attributes['cols'];
Entered your desired dimensions for the numbers in purple.
I still cant figure out how I disabled the TinyMCE for the user registration page....