Per Fr. Hesse, the difference between the formulas in the old and new rite do not invalidate the sacraments used in the new rite.
Many, many Trad clerics disagree. Fr Hesse isn't (or didn't start off as) a Trad priest. He's obviously going to shill for V2. It's appalling that you can't see the bias here.
When there is doubt, the Church sides with the sacraments
No, this is contrary to canon law.
Once you change a sacrament, it's no longer from the Church.
A. Major - The Church presumes validity for sacraments which are a) approved, b) by Apostolic Authority, c) under pain of sin, d) for the entire Church.
B. Minor - V2 sacraments do not fulfill the conditions for either a, b, c or d.
C. Minor 2 - The only sacraments which are true are the rites coming from Pope St Pius V and Quo Primum. These fulfill all conditions for a, b, c, d.
D. Minor 3 - The Church only has 1 rite in the Latin Church. She cannot and does not have 2 rites at the same time.
E. Conclusion - The Church does not presume validity for sacraments She didn't approve; V2 sacraments are not true sacraments, but in name-only.