The first issue:

It seems that sometimes when I hover to the left edge of the screen the Unity Bar will not stay on top of other windows even if I continue to hover the cursor above it, at other times it will stay on top.

Is this a normal behaviour? Or am I affected by some bug / inconsistency? If it's normal, what's the logic behind it?

The second issue:

Application icons for running applications do not maintain their position in the Unity Bar but instead move around according to some weird rules (if any?) that I can't understand.

Is this to be expected, or is it a bug? Is there a way to force them to stop moving around? I like to see certain apps in certain positions and this bothers me.