I also think the grass moves too quickly, i'd cut the speed at least in half. Btw, are do the animations continue when the player is moving (unaligned)?
Animation is kept mostly smooth during walking, but as the screen is shifting, animation is kind of halted. It is still managed, so the frames stay on the correct time, but the tilemap is only redrawn once the scrolling has stopped (I use flags to indicate that the tilemap was supposed to be updated mid-scroll). As well, any newly scrolled in tiles that appear under the player are updated with the new data, so there may occasionally be a discrepancy in the correct frame used. It is difficult to notice for me unless I turn the emulator down to a really slow speed, but it shouldn't cause any problems.
Also, thanks for the input about the animation speed. The delay is currently half of the maximum, so I might need to include an extra counter.