It's an Iranian oil tanker no matter what it says on the paper work.
Not necessarily - on what basis is it Iranian? The cargo apparently is, The tanker is owned by a company in Singapore, whether the owners of that company are Iranian or not we don't know unless you've got some additional information you'd like to share?
If you are all for this then great, then I expect your support of Iran's actions when they seize British tankers based on their own arbitrary legally unenforceable sanctions.
That depends on the situation, I'm not sure why you'd automatically expect that. I've explained this already and pointed out that if you have trouble understanding part of the explanation then you only need to ask.
Oh, the 'bloody' Assad regime...please. Have you arrived in a Delorean from 2011? Assad has been fighting our pet jihadis and winning hence the hatred of him.
Yes the Assad regime, that is the reason for the EU sanctions! The UK doesn't currently support the US sanctions on Iran (in fact the EU is about to go live with a trading mechanism designed to explicitly undermine them), the reason/legal basis for stopping this vessel was in relation to EU sanctions against Syria!