1) unit tests
2) unit tests
3) can be a CLI switch instead (and not required for the listenserver at all, since it doesn't keep running when nobody is playing)
4) this one would actually require proper testing, to see if it at least doesn't actually break the game somehow
5) can technically be ignored, if defined as "unsupported configuration" (been done before)
Potentially doubling - yeah, okay. Actually doubling? Doubtful. This is a rolling alpha release; most stuff that isn't directly affected could be relegated to bug reports, assuming all that many people actually end up using the option. Consider: the game is expected to run just as if there's a player attached (so most issues are already tested for); if it doesn't in some way rely on client feedback to run, not all that many components should theoretically be affected (and if it does, this would be a sizeable changeset, which puts it outside of scope in a hurry).