Interactive function with two functions

Question

Would like to have an interactive function that enables or disables two features (either auto-complete or company). Is this how I can use the interactive clause to pass two function arguments? I get confused because customarily, let returns only one thing, the result of the last command.

(defun complt (featr actm)
  "Enable or disable text completion."

  (interactive
   (list
    (let* ( (cseq '("acomplt" "company"))
            (cftr (completing-read "Featr: " cseq nil t "company"))
            (csel (completing-read "Actm: " 
                     '("disable" "enable") nil t "enable")) )
    cftr 
    csel))) 

  (message "DO THIS") 
  (message "DO THAT"))

Answer 1

Indeed let returns a single value, while for passing two values via 'interactive' you would like to pass a list containing two elements/values,

therefore, just place the list inside the let as follows to get what you want:

(defun complt (featr actm)
  "Enable or disable text completion."

  (interactive
    (let* ( (cseq '("acomplt" "company"))
            (cftr (completing-read "Featr: " cseq nil t "company"))
            (csel (completing-read "Actm: "
                                   '("disable" "enable") nil t "enable")) )
      (list cftr csel)))

  (message "DO THIS")
  (message "DO THAT"))

Answer 2

Yes, you have confused these two things: (list (form a b)) and (form (list a b)).

I think a simpler way to write this avoids let entirely:

(defun complt (featr actm)
  "Enable or disable text completion."

  (interactive
   (list
    (completing-read "Featr: " '("acomplt" "company") nil t "company")
    (completing-read "Actm: " '("disable" "enable") nil t "enable")))

  (message "DO THIS")
  (message "DO THAT"))

Here is another version using let:

(defun complt (featr actm)
  "Enable or disable text completion."

  (interactive
   (list
    (let ((choices '("acomplt" "company"))
          (completing-read "Featr: " choices nil t "company")))
    (let ((choices '("disable" "enable"))
          (completing-read "Actm: " choices nil t "enable")))))

  (message "DO THIS")
  (message "DO THAT"))