Public WiFi behavior

Here's an observation: My apartment offers free wifi around the social congregation areas. It is not encrypted BUT as I have observed, each connecting device is confined to its own VLAN (based on MAC address I guess). So you really cannot fiddle with anyone else's data (or can you?)

To start surfing, the user needs to first press an acceptance button, and then only is the Internet activated. But this does not hold for google websites (search, gmail, etc.). I am wondering:

1. What is the ISP gaining by offering unrestricted access to Google?


2. Given the security params of this WiFi, is it secure to do bank transactions?


3. What kind of attacks can be pulled off here? My first impression is MITM is not an option (but please correct me).