Really, it's about the same.
You can have something like 64 quintillion addresses per /64
As far as RA or DHCPv6, it's really up to you and what you're trying to accomplish. The last I knew, even if you did DHCPv6, you'd still need to do RA so they hosts were able to set the default gateway.
As far as the addresses, again, it's up to you. You can use the same connotations as you do with v4; Use ::1 for the firewall address or ::254 for the switch
What would a host entry look like for 2001:db8:1:1::/64?
I'm not sure what you mean I guess....to have a valid address, you need to add something after the :: 2001:db8:1:1::1 would be a valid address