Hi Rob,
The trip to Valencia gives plenty of opportunity to photograph the street life. Especially when we're visiting the older parts of the city there will be ample street life to photograph. But even at the arts and science park there is more than enough going on to not get bored

For the street photography, the Nikon V1 will be a nice camera. Perhaps even for the buildings, this will be usable (depending on the type of shots you're after) If you can I'd still take a DSLR with a good (wide angle) lens with you though. Your D3x would be awesome here!
Valencia is a great city with beautiful buildings and a nice relaxed atmosphere and people. Great subjects for street photography.
Hope this answers your questions sufficiently.