does the following also apply if a Tor users chooses to use a bridge? - We do not choose more than one router in a given /16 subnet
[1]Will tor ensure that the relays are not in the same /16 netblock with the bridge?
Yes, as each node is added to the path, its IPv4 address is checked
against the IPv4 /16 netblocks of the existing nodes in the path.
This includes relays and bridges.
There is no support for checking IPv6 addresses yet:
But when there is, we will check IPv6 /32s, for those nodes that have IPv6
addresses.