Trying to run lines on a timer
You can add WAITFOR DELAY between executions. 

UPDATE que SET status = 0 WHERE doc = '001'; EXECUTE [things] '001';
WAITFOR DELAY '00:00:10';
UPDATE que SET status = 0 WHERE doc = '002'; EXECUTE [things] '002';
WAITFOR DELAY '00:00:10';
UPDATE que SET status = 0 WHERE doc = '003'; EXECUTE [things] '003';
WAITFOR DELAY '00:00:10';


Might be a good idea to add some (error) logging as to know where it failed if an error occured.

If you don't want to write 50 extra lines, you could use search and replace in ssms (CTRL+F) and replace 'UPDATE' with 'WAITFOR DELAY '00:00:10';  UPDATE'



Make sure you are on current document and then press replace all:



Result: