Hi Sooz.

Your point about protien storage is correct, but vegetables also contain protien and an excess of vegitable derived protien would be excreted after breackdown into ammino-acids in just the same way as animal.
Meat has the advantage over vegitables in that it contains all the essential ammino-acids in one hit, to get the full range from vegetable sources you have to mix and match. Meat is also rich in fat a vital imput to an energetic and relativly short intestined species such as ours.The short intestine is a result of a bigger brain and both processes involved us in adopting a high quality diet containing 30% of callories as fat. This diet would have been imposible on vegetables alone in Africa at the time of becoming omnivours.Meat eating also led to important technological developements that fead back into increased brain size.
As to the morality of eating meat, wether you like it or not Life eats Life, and without the preditor pray relationship there would be no intelegent species on this planet. This is the way the Universe made us so were do you stand to say its wrong.

All the best PP