I actually teach initial CFI training so I know endorsements like the back of my hand. 1 is required for every checkride so that is correct. If there is a knowledge test required you also need 2 if they did not get 100% on it. You would need that in scenario 2 you posted but scenario 1 is staying at private pilot privileges so a knowledge test isn’t required.
For scenario 1 endorsements 33 and 32 are not required because it’s an additional category/class rating, not an initial certificate. i.e. adding a rating onto a private certificate. You would only need endorsement 73 instead for training under FAR 61.63
You would never need endorsement 71 for a checkride because it’s specifically for a rated pilot to fly solo, an examiner being on board makes it not solo. But it could be used for the solo time time required for the commercial certificate, just not required for the checkride
For scenario 2 you would use the 34 and 35 endorsements since it’s the initial commercial checkride.
For scenario 1 it would be endorsements 1, 67, and 73, and for scenario 2 it would be 1, 2, 34, 35, and 67
Hope that helps!!