Whenever I make movement and motion paths in motion it always seems to come out a little jerky. I create a motion path then I use keyframing to turn the arrow in coherence with the motion path. I tried placing multiple keyframes per major turn and I also tried just making fewer points and using more of a diagonal keyframe path (the keyframe line in the keyframe editor was diagonal) as opposed to a more rounded path created by more keyframes. Nothing seems to be giving me the smoothness of movement that I want. Is this just due to limitations in the program?
Without seeing your project it's hard to know exactly what the problem is, but you should be able to get smooth motion. Here are a couple things to try with what you're doing:
Instead of manually aligning the arrow's rotation, try using the 'Snap to Alignment' behavior. This will automatically turn the arrow in alignment with the path.
If you do manually keyframe it, make sure the keyframes are set to bezier. It's usually best to try and use as few keyframes as you can, but you'll probably have to get into the keyframe editor and finesse the curves to get the smoothness you want and the timing you want.