It honestly looks like you're packing an awful lot in to such a short time. A week in Paris, Rome, or Barcelona, is barely enough time to get a good feel for the cities. A day? Wow. I predict you will be very worn out with this fast paced itinerary. Also keep in mind that the first day in Paris could be pretty worthless with jetlag.

Look at trains. They are so much easier than flying.

I know this isn't likely the kind of stuff you want to hear, but I would cut Ibiza and Barcelona, just because the trip could be easier.

Could you fly into Rome?
Fly into Rome, train to Venice, train to Zurich, train to Paris, train to London

With your current itinerary, I'd say Paris to Venice, Venice to Rome, Rome to Ibiza, Ibiza to Barcelona, Barcelona to London, would be the best way to travel.