Re: Aikido and inner aggression
I think whether aikido is a good way to help you with your anger or not depends very much on how your anger manifests itself, how you react to aikido, how you interact with people, etc.
It could be good but it could also be bad, either for you or for others. Angry people on the mat can be incredibly destructive to other people on the mat, and in some cases even physically dangerous given how much concentration is needed to stay safe and avoid accidents. Other people are there to train and learn and each also has their own personal history and personality, so it's important to be careful that you aren't asking them to deal with your anger or behaviours that it causes.
Personally I'm inclined to feel that someone who has trouble with anger is the last person I would want to join my dojo, but OTOH if they can keep it to themself and keep it from negatively affecting others that's very different.
So just be very honest with yourself about your own behaviour on the mat. Consider whether your training is good for your PARTNERS as well as for yourself.