Tarnish,
Try flying a turn at 250Kt when the obstacle clearance is based on say 185 Kt just because you were told "no ATC speed restriction" or "free speed" or something like that and you will get a lot closer to the obstacles than your boss would like.
Several other examples.
However, if ATC say "no ATC speed restriction" I than them for removing the ATC speed limits (subject to airspace class, I can increase speed in a straight line to just short of the speed of sound) but I am the one responsible for obstacle clearance and in some cases traffic avoidance.
Therefore, I think that ATC, the CAA, my colleagues and my boss still expect me to do my job and not fly round the corner at too high a speed straight into the obstacle that the standard procedure speeds would have kept me clear of.
You are quite right - I do my job and ATC do theirs. Lifting an ATC speed restriction does not mean that I can ignore other safety speeds.
Do you take "Free speed" to mean that you can exceed some aircraft speed limit (VFE or VMO or MMO?) No. Same goes for the other limits that you have to comply with such as for example the speeds that your obstacle clearance is based on.
Get the idea?