1) Can Aikido be used for Self-Defence?

“Those who are skilled in combat do not become angered,
those who are skilled at winning do not become afraid.
Thus the wise win before the fight, while the ignorant fight to win.”

Yes, Aikido can be a very effective form of self-defence. However, it can take considerable time and effort before Aikido (or any martial art) can be used effectively in a self-defence situation.