After finally managing to connect to it with Winbox, I first ran this command:
Then, I ran commands similar to those found here. The only notable differences being that I chose 192.168.144.0/21 as my network. A dhcp client is set up for ether1, a dhcp server is set up for bridge and both of these work... if my cable modem is plugged into ether1, it gets an IP address from the ISP. If a computer is plugged into any of the other ports, they'll get a 192.68.144.x address.
/system reset-configuration no-defaults=yes skip-backup=yes
Then, I (somehow) managed to get Capsman working correctly after several false starts. I can connect to the ssid, and I get 192.168.144.x addresses with those as well.
But this isn't currently usable yet. I've tried to set up NAT, and I think it should be rather simple right now... my requirements are pretty minimal. I think (but am uncertain) that it should be a single firewall rule like so:
I do remember that this isn't the exact same command I had written (I was working off some other copy of this... it even spelled masquerade wrong, and I was confused about that until I counted over 71 characters to where the misspelling was indicated as a syntax error). In particular, I think the position of out-interface and action were switched so that the former was the last part, like so:
/ip firewall nat add chain=srcnat out-interface=ether1 action=masquerade
Should that matter? When I use the UI rather than the terminal, it seems to have liked the command just fine. But when I switch over to my new Mikrotik router, I have no internet connection through it. In the tutorial I was working from, it suggested that the connection tracking table needed to be nuked, but gave no explicit commands for this... I eventually found a set of 3 commands that basically did something like "tracking enabled=no; delay 5; tracking enabled=yes". The tracking table (forget where I found it in Winbox) did indeed clear out, and then eventually fill back up. This did not change my connectivity problems.
/ip firewall nat add chain=srcnat action=masquerade out-interface=ether1
It's difficult because once I cut over to this router, I no longer have internet to try to troubleshoot with and have to go about hooking back up my old router again. I intend to post the configuration dump in a few hours when I'm off work and have can do so. But I was hoping that in the meantime my description of the steps I've taken might make it obvious that I've left something out. Thanks in advance.