Did you previously have the domain set to “fully hosted”? The error you are showing in #3 indicates that the traffic is reaching a dreamhost server.
I suspect your problem is that you are not waiting for DNS propagation after making your custom A-record. DNS can be tricky because the length of the time it takes for your change to take effect can be anywhere from just a few minutes up to a full 72 hours (3 days) and not everyone gets updated with that change at the same time. For the most part, DNS changes become effective about 4-14 hours after you make them. I suspect your error will clear up with time, assuming that the IP address you are using for your custom DNS is correct.