Main question of bachelor thesis can be, is Taijiquan related to Taoism or was Taijiquan found, established by, from Taoism/Daoism philosophy? What principles, tenets Taijiquan has, are these tenets related to Taoism? Are there other principles in Taijiquan that are not from Taoism? School of Yin-yang and school of Five Elements are even older than Taoism, they were absorbed by Taoism.
Sun Lutang master in martial arts wrote many books about martial arts. He is trying to connect, put together philosophy and martial arts. In his books he mention philosophy a lot related to Martial arts. Some of his books should be thesis sources/references.
Main topic of this work should be Taijiquan and philosophy but also can be mention fact that Taijiquan is not primary healthy exercise or kind of spiritual study, discipline but it is primary martial arts.