Father Ripperger is a priest in good standing in the Church. I believe you are correct in saying that if he was a heretic it would be a difficult for him to carry out his ministry, especially in regards to exorcisms. There are some here at CAF who will speak highly of him (myself included) and others who will speak very critically of him. He is a priest who supports the traditional movement. I have never heard him say anything heretical, though he can ruffle some progressive feathers and be pretty firm with traditional Catholics also. He lays it on the line pretty straightforward.
I am glad you stated the Novus Ordo Mass is a valid Mass. I have never heard Father say it wasn’t.
I understand Father in this particular talk (and book) to be clarifying Tradition, what it is, how it works in the Church and why it is part of the authority in the Church along with Scripture and Magisterium and why it is so important. He always uses Scripture, Church documents and Papal quotes, and encourages obedience to the Church in his talks so IMHO I do not see what would be refuted.
As far as what would support him, my suggestion is the Roman Catechism from the Council of Trent. He suggests reading it and so has my priest at my Catholic Novus Ordo/no EF Mass at all parish because it is very straightforward and clear language and the foundation for every other catechism.
I am not sure if you have been to Father Ripperger’s website or not but there are quite a few more talks there: