skypilot35,
You need to read Flying the Line, then come back with questions. RLA basically rules out cross-company or national unions covering several companies. The RLA was written to prevent strikes or lock-outs crippling transportation., not to give either the company or union that much power.
As to transferring jobs, if you can't have trans-company unions, explain how to get to national seniority? Before that, explain how to operate a large number of interchangeable members of a craft except thru seniority?
As to pay, google Decision 83 of the National Labor Board
GF