Joining the euro isn't as big a deal as some people would have you believe. You just promise you will some day, then kick the can indefinitely.

Iirc you have to agree to adopt the euro once you meet a particular set of criteria, so countries who don't want to join just make sure they don't meet the criteria.

Very true, Brits might be more sceptical about rejoining the EU if adopting the Euro were a condition.

Also, freedom of movement is a slightly different thing to the Schengen Area. The UK previously had freedom of movement with the EU (allowing EU citizens to live and work in any EU country) but the UK was not in the Schengen Area (where border controls are minimised, allowing passport-free travel). Because the UK was not in the Schengen Area, a passport needed to be shown when moving between the UK and any Schengen country.

Freedom of movement is definitely a condition of being in the EU. I don't know if the UK would be required to join the Schengen Area though. Ireland and Cyprus are two EU countries outside of the Schengen Area: Ireland apparently is not obliged to join it, but Cyprus is.