FS - I think your explanation just about sums it up, any difference from my understanding of the subject, I suspect, come down to semantics.
Helmet - I have to say that the logic chain falls apart a bit at point 2.
a) Speed can not be thought of as directional! - A body moving in a circular path may well have a constant speed, in which case it will have a constant acceleration and constantly changing velocity. A car travelling at 30mph on a roundabout has a constant speed, i.e. it covers 30 miles in every hour. It is, however, accelerating constantly towards the centre of the roundabout.
b) "An acceleration is a force" not in my book!