The EU doesn't impose it's sanctions on non-member states like the USA does and Iran is not a member of the EU, therefore the EU sanctions on Syria do not apply to Iran.
This is why the EU is being so quiet on the subject, because in it's eagerness to please the USA the UK has "done gone messed up" and if the EU did decide to become vocal about the subject then it would have to side with Iran, hence the silence.
You're wrong. See explanations above.