hey,
um.. i'm not sure about the angles thing.

if you need constant velocity then my suggestion above of "use this to generate some points, then use your normal constant-velocity straight-line pathing" is probably the best thing -- it's simple and you know it will work: just start at the first point in your original list of points, then (stepping along the parameter at a constant rate) get a point on the curve and store it in a list of "points on the curve". then, use this second list with your straight-line algo instead of the first "coarse" list when moving people around.

trying to figure out how to move along a curve at constant velocity sounds like a huge headache to me. if you must, there are papers on this -- specifically, many 3D games use splines to move the camera around during cutscenes, and i'm positive i've read at least one paper on how to get constant-velocity movement over splines in realtime. but it's not likely to be cheap or easy..

raigan