Re: 2 Martial Arts
Here is a quote often attributed to Imi Litchtenfeld, founder of the Krav Maga combat system "If a man comes to kill you, kill him first". His holiness the Dalai Lama once said "If someone has a gun and is trying to kill you, it would be reasonable to shoot back with your own gun".
As above it depends largely on the situation that you find yourself in, if someone wanted to attack me and I genuinely believed that I was going to be hit, then I probably would take a pre emptive strike/s to end it. If you are going to use an Aikido technique to plant an attackers face into the concrete or a kitchen benchtop and break their neck and so forth then I see little difference between doing that and striking.
There is a world of difference in my opinion of being the first cause of a violent assault and using a pre emptive strike to defend yourself.