You might be confusing this with the Switzerland situation. The EEA states (Norway, Lichtenstein, and Iceland) indeed must take all legislation that’s part of the EEA into their domestic law. Sometimes directives and regulations have cave outs for countries but they’re rare.
Implementation is overseen by the EFTA Surveillance Authority who can sue members in the EFTA court.
No, they don't really must accept all rules. Only the ones that will benefit them. This will cease once they join the EU.