1. Use the IP and Port specified. If you recieve ID 15, the person may not be hosting correctly.
2. People who state localhost as the ip will always have invalid servers. LOCALHOST redirects to your own server/computer, NOT as an actual IP.
3. There is no other way other than using a number IP or joining somebdy with a website DNS instead of an IP (which is complicated in itself for the hoster only)
4. Server lists may exist but I'm not sure. Making a website for a server list or making an official server list is making a website and Bitl doesn't have plans for that I don't believe.
5. Currently the only way to find and join servers is through YT (but almost all the ones there are either hidden, down, or made by underage people) or the Unofficial Discord Server (which i forgot the link to.) Do not join it if you are under the age of 13, you were warned.
6. The feature is present.
If you are in the discord server, I will not be present, sorry!