Re: Should I get in better shape before starting?
I did lots of sports, and intensively so, although without any talent or success, until I was 18. Then I moved away for university and dropped them all. The only movement I did was walking to the bus stop or cycling to some very nearby places.
I started aikido 20 years later and didn't even feel I was out of shape. Probably because I started slowly, one lesson per week, and then gradually increased up to 4 times per week + all seminars possible.
After 7 years of aikido, I have the impression I'm in pretty good shape. I still get easily out of breath, when doing dynamic techniques for a time, but on the other hand I quickly recover my breath again and can continue at normal or high speed (teacher explaining new technique allows to recover...) for a long time.
So in my opinion the good physical condition comes with the training. Just don't go beyond your limits at the start. Anyway, you will discover new limits you didn't even know about before, such as flexibility, intuition, sense for distance, reaction speed, equilibrium etc....