Jumpman, I would also like some replies for that skill usage query.

If appropriate, I just loosely work off the following:
Some elements are relatively common among classes of object, and once defined, such skills can be reused across similar classes.
Other elements are fairly unique to certain classes of object, and those skills are not shared to the same extent.
Common, re-used skills can be assigned to a certain range of skill numbers as a standard.
Unique skills can be assigned to a different range.

It seems you are an experienced user, so I will assume that you have squashed that bug successfully some time ago.