Don't know about Iceland, but Norway and Switzerland have had to actually adopt the EU norms without having any say in how those norms get adopted or decided. That's the reason they didn't go "down the drain", I think you forgot to mention that.
Trade norms are not a bad thing, even if some in Britain wanted to continue to sell bananas by the lb. Most everyone is happy with having trade norms, and in particular, having the same norms everywhere (not just in EU but world-wide, starting with things like the metric system).
Unfortunately, even within EU the influence of small countries on trade norms is rather negligible. We also get lost of proposals for regulation of things we don't want and could avoid outside the EU.
Note that I'm actually for the continued EU membership of my country. I just find it abysmal that the pro-EU camp is often in denial about things and too enthusiastic for deeper integration towards USE.
