Love and War; and Some Gandhi

The famous saying 'All is fair in Love and War' lead me to feel these emotions as kings[or queens] of all other emotions. When these emotions peaks, hardly anything can contain him from within. No ethics and certainly not other emotions. Love[and war] will find its way out.
Almost all other emotions can be roughly categorized into either emotion. For say,

LOVE	WAR
Kindness	Anger
Compassion	Hatred
Pity	Greed
Sympathy	Jealousy
Empathy	Disgust

Of course, not all can be accommodated in these two. There can be some more basic emotions like sadness. The three basic colors combine to form hundreds of colors, Similarly, we have emotions.
Or some like Robert Plutchik goes with eight basic emotions, 

Fine, why I'm into all these?

Some eternal questions always puzzle me, like,

Rationality Vs Emotions; Which forms the basis in human evolution. 

For say, let's take ethics[truth in Gandhian parlance]. How and why it evolved? The basis is as much rationality[which is good] as emotion[compassion, sense of justice].

Being a Gandhian and Devil's advocate, can non-violence be imbibed in humanity eternally? His two eyes were Truth and Non-violence. I always question myself on the later on both its necessity and possibility. Both Love and War are basic emotions of humans since time immemorial. So can such a basic emotion be overcome?