You need to convince them their demands are UNECESSARY to ensuring you won't exploit their market openness.
Ergo things you might consider not doing:
EU regulators believe their settings are about the right balance of achieving objectives (environment, etc.) and imposing costs.
Doesn't scream, "you can take our commitments on faith, no need for legally binding rules or procedures."
Seriously, the EU isn't stupid. They know that "sticking it to Brussels" is a tempting applause line as it is.
Hiring people who think norms are optional doesn't hint at a lot of restraint there.