[FloareTraurne]

Since school days, I have trained in Karate (Gojukan of Hanshi Gogen Yamaguchi) and have a black belt in it. But I am developing interest in Muay Thai nowadays.

the original muay thai has a lot of Buddhist/animistic rituals, so be careful when searching for one or learning from someone.

I am still fairly young (22) and I was thinking about practising Kyokushin Kai Karate, but you have
to bow for example to the teacher and to your opponent, within Japanese culture it's not a form
of worship or something but merely as respect or a sign of humbleness.

Is that permissible within the Sharia if the intention of an action is not wrong?
How did you deal with that?

If you are in Nederlands, look for Indonesian silat.