Square vs. Anamorph should only affect the horizontal scaling, not a problem with a vertical scroll.
Q: Did you render the animation out without using Fields ?
Using Fields, it will look crappy on the monitor, but much smoother on a video. (if you choose the correct field-order !)
If you’re not outputting to film or the web (other media than TV or DVD), absolutely render with fields.
I always add a gaussian or fast blur of less than a pixel (0.25 – 0.5) to any text layer.
Also, many people add an expression to the position after setting the keyframes so the text will always fall exactly on a pixel value and no differences in anti-aliasing of text occur from frame to frame.
the expresssion is:
[value[0], Math.floor(value[1]}]
Sometimes this gives better results:
[value[0], Math.floor(value[1]}] + [0,0.5]
do some short test-renders with each of these tips, and decide what works best for you.