I'm new to the system and have been toying around with making new characters in my spare time.

In the process of making a Tao, I decided to work towards the end-goal of having both Excelion and Rex Frame, which means I require Kardad/Tai Chi and Malla-Yuddha/Muay Thai. I decided to go with Tai Chi and Muay Thai to start, due to the heavy damage of Muay Thai and lovely MK boost of Tai Chi.

My question comes with the combination of these in practice. Dominus Exxet says in the supreme degree of Tai Chi that the Power bonus may be applied to the base damage of any other martial art. Would this still allow the Strength modifier of Muay Thai to be used, or would I be better off taking Malla-Yuddha for the higher flat base damage?

I know there are other factors at work in each of my choices, but I'm concerned with the rulings on damage in these at the moment.

When it comes to damage from a martial art, you must choose 1 damage from the combined martial arts, which include its bonus. So no you couldn't have both Str of Muay and Pow of Thai Chi, Its one or the other as it states in the martial arts section of the book.

As cdcace said, you can only choose one damage of all the martial arts known. BUT in the case of Thai Chi supreme, the power bonus can be added in addition to what ever is said as the base and stat bonus for another style's damage.