More resistance equals slower moving liquid and more wear and tear on your pump and sucks up more power...
And yeah if the order you have posted is the flow direction I usually see the normal as the opposite of what you have, but with the rads in between everything I don't really see any issue with it.
Side note, are there fans on the top rad where you cant see? because if there aren't and if thats your post CPU rad you might want to put a fan on it otherwise its not doing too much just your extra case flow moving air and warming your chip set
Edit: just looked up your pump it has a Maxium head of: 10 ft (3.1 m) so looking at your setup it seems to me like you have around 11-14 feet of flow... you may want to consider getting a larger pump, or adding another mid loop where you can...
(If this is actually the pump you have)
http://www.overclock...id=2141&subcat=