I never got the impression that Odo was especially intelligent. Not dumb and perhaps above average, but certainly unremarkable compared to Data. And is his strength above average? He certainly knows how to handle himself in a fight and his shape shifting gives him some unique advantages, but have we seen him exhibit strength above and beyond the norm?
Using your arms, shapeshifting or no, to stop a turbolift from falling by warping it out of shape to jam the shaft seems like a display of strength above the norm.