3 way, who thought it would be easy in a 70s house?

Switch 2.

This is where I don’t fully understand what I’m supposed to be rewiring. Are load/trav interchangeable?

Does it track that the SE/NE corners of the fixture box must be the ones I need to worry about?

It seems like I don’t have enough wires to do this.

Does it matter if I use a separate neutral on the Aux Switch?