The Bianchi Volpe is not a road racing bike, but a practical all-round road bike ideal for your use. You dont always need to wear cycle racing kit to ride, it depends how far and how fast you want to go. You dont always have to ride at max effort for utiltiy cycling.
I am prepared to sacrifice the efficiency of clipless pedals for the utility of toe clips. In your climate, you could probably make use of those SPD cycling sandals.

Check out some of the triathalon wear. They may have some solutions to swimable cycling trunks. You could wear MTB style baggy shorts with padded inserts over your trunks.

I usually lock my helmet to the bike rather than carry it around. My cheap model has few large holes, so the shackle fits through the holes. More modern designs have many smaller holes, so you will need a thin cable. Look for one with a loop at each end, and you can slip it though your lock.