Can anyone...

I think of imbalanced as on the same scale, but on the opposite end, from symmetrical.
I think of dynamic as involving things like initiative, open kings, hanging pieces and pawns, things like this. The opposite are static features like pawn structure.
So very imbalanced but not dynamic might be a maneuvering endgame position where a player has a rook and 7 pawns vs two bishops, a knight, and 3 pawns.
A dynamic but not imbalanced position would be like one of those big attacks you can see in the french exchange. Symmetrical pawn structure and the same number and type of pieces for each player, but one player has a huge attack because they have four pieces in front of the opponent's king.
imbalanced means that the type of advantage is different.
That's more to the point than what I said IMO.
It,s not that easy to me unravel such a conceptually hard stuff. At the end of the day it appears to revolve around short-term vs long-term assets. Actually my concern is to sufficienly handle a concept wich is frecuently mentioned by lecturers here in chess.com. Paricularly when I track GM Melik,s lessons I find he,s overwhelmingly profuse on using this.. maybe unconcious that such a subtle concept demands some restraint or at least a clearer/slower management.
Dynamic vs static is like short term vs long term. Dynamic like initiative vs static like pawn structure.
For imbalanced maybe just think of it as unclear. I like how FOS put it though.
Maybe these would help you:
http://www.amazon.com/The-Middlegame-Features-Algebraic-Edition/dp/1880673959
http://www.amazon.com/The-Middlegame-Book-Subjective-Algebraic/dp/1880673967