I use my passport for everything too. To avoid the awkwardness of having people flip through the pages I purchased a passport holder on ebay (super cute) & I put the passport in a way that when you open the holder, only the ID page shows, the rest of the pages are shoved inside the actual holder. If someone wanted to flip through the pages they would have to take the entire passport out of the holder & it's kind of difficult & a pain too (so nobody ever does). If someone ever tried to do that I would just ask them to give it back (here I'll do it!) and once in possession of my passport I would just leave, hah.