One of the things I recall about this lesson is that Michael didn’t do anything special for importing the animations from what they were before the change to the Rotation. So, as long as the Armature and Object have the same rotation, it shouldn’t matter how you orient them afterword. In fact, you could even skip rotating them back so long as you are prepared to work with Blender with the Y-axis as up (that means doing a lot of conversions in your head).
As for the textures, as long as you aren’t using procedurals you shouldn’t have to worry. If you are using them, you’ll have to bake them out anyways before you can import them into Unity so it’s no big deal. The orientation of the model doesn’t matter when using a UV Map to map your textures.
With these things in mind, I would suggest the following:
- Create the Model
- Create textures
- Bake any procedural textures and reapply
- Rig the Object
- Create Animation
- Adjust and Apply Rotation for Export
but that’s just me and I really really really don’t like doing animation work