Q6. The excitation is placed to along the edge of the mesh, so when two ports cross each other, they have electrical connection, which is not the kinda feed we are interested.
Q7. You may try something like the given in the attached simple dipole model. You will still keep the original phase difference. To be even safer, make sure that those feed lines are at least two mesh cell apart (so that they don't belong to same cube (i.e. hexahedral)) You can see your mesh from "mesh view". Select "z normal" and by hitting up and down arrows find the plane that your ports are at.
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