The problem of the Euro is that you cannot have a monetary union without some kind of common economic governance.
It means that the UK is freer to decide its economic policies in its own interests rather than having to be limited by the needs/preferences of other countries.
This is true, from what I know the UK saved its economy by undervaluing its currency. It would not have been able to do that if it used the euro.
And if some countries (ie Ireland) had not been in the Euro, then they would not have had such a big bubble in the first place.
I don't think this is correct. Can you give a source, a analysis that demonstrates this? If every country from the eurozone would have respected the EU rules probably the problems would not have been so great for them (but of course, the EU cannot take action against those that behave bad because some fear loosing their independence).
Take into account the fact that Iceland wants to join EU just because it would have been less severe hit by the economic downturn if it would have been a member of the eurozone.
Of course, being a member of eurozone has both advantages and disadvantages. It is up to every country to weight both and to make a decision if to join or not this zone. For the continental countries, I think that the advantages are greater than the disadvantages.