On dispute settlement, the dispute settlement system as contained in the Canada-EFTA Free Trade Agreement is a very simple one. Each side chooses one arbitrator and then the two parties that are in dispute choose the chair. It's the classical arbitration model. It's even called an arbitral tribunal, so it's very simple.
On the preamble, yes, the preamble is not excluded from dispute settlement. If a hypothetical question of environment or labour were to come up, one would have to figure out to what extent the preamble contains an actual obligation. A preamble generally is not viewed as containing obligations as such; it is more an introductory statement.