Hi, Sabatino
1. I can replicate this. After the rule is created, though, it appears the "Enable wildcards" setting WILL remain if you toggle it on after setting your Conditions and Actions, it will remain. I'll get this written up, though, for the devs.
2. "Use IP X" will need to be a feature request. I'll write that up as well. This is the first pass at Routing Rules, so we knew we'd be adding in options as we move forward.
3. "Is Being Forwarded" refers to "automatic" forwards that can be set up, or via content filtering. However, I don't believe it's only external forwards. You could limit that by adding a To Domain Condition, and the comparison "Does Not Contain" and list any internal domains.
4. Right now, it's available IPs. As for "[i]f it starts working" -- I'm not sure what you mean. Someone did have an issue, but they resolved it themselves.