Keane would be a disaster of a manager.
If you look at the managers who have been very successful over a period of time, most of them are essentially master psychologists. Ferguson, wenger, mourinho, and without going through a long list I'll just say Trap and leave it there. These are all highly intelligent, driven, capable people, who would have been an enormous success in virtually any other walk of life.
These people are master manipulators. (not necessarily in a bad way) They understand how to get a player to do what they want to do. They can put themselves in that players position, and say the right thing to him.
Keane simply doesn't seem to put himself in the other person's position. For all of his other attributes, he has a near total lack of empathy, and that is an insurmountable obstacle for any would be manager.
Sheer undiluted, terrifying rage is a powerful tool in any manager's arsenal, however it is only one interpersonal approach, and one that should be used sparingly. It is also one that should only be used entirely cold, i.e. the manager has to be entirely in control when using it, otherwise it can become seriously counter productive. I don't think that roy is always in control of his anger.
That and he's not much of a coach, or a judge of player, or a tactician. I think he should stick with the TV punditry. We need a resource maximizing manager. Someone who will scour the english leagues, watching every irish qualified player. Get them all on board, and organize the team in an effective way. Roy keane is not the answer. I wouldn't mind giving kerr another go. There's no-one left from his last time in charge, and the available squad is filled with impressionable players who are just dying to play for ireland.