Suit Jacket Length
Altering a jacket's length is difficult to do and simply not worth trying, in my opinion. Am I correct in assuming that you are after a chopped look? As for the pants, they're fine as long as you don't mind looking like you borrowed them from your shorter brother.
What's with the trouser hate? They look fine.
This isn't exactly so. Arm length can vary greatly and make this "rule" troublesome. A more useful rule, though still with its limitations, is that the jacket should entirely cover ones seat, and roughly extend down to half the body length.
From my memory this suit jacket covers the butt.