Two i7s changes my earlier answer in one place and not the other.
The map
Your paint version is what the room is; the robot’s version is where it has driven. That gap does not close with more missions — furniture stays where it is, and a step the robot cannot cross is a wall as far as it knows.
But on an i7 the shapes come from the robot’s own saved map, not from anything we reconstruct. So what you are looking at is iRobot’s map of your home, drawn faithfully. If it is wrong there, it is wrong at the source, and nothing on our side can correct it.
Map editing exists for Prime robots — renaming, splitting, merging — but the i-series uses a different protocol for it, and it is not built. Redrawing an outline the way you did in paint is not something either protocol offers: the app cannot do it, so there is no command to imitate.
Zones
Better news. Zones on i-series robots are readable, and the next release draws saved clean zones on the rooms map — outlined, so they read as a marked-out part of a room rather than a separate one.
Creating and editing them from Home Assistant is being worked on by another tester and is not merged yet.
What you describe — drawing round a carpet to include or exclude it — is exactly what keep-out and no-mop zones do, and those are the ones in flight. So: not now, plausibly soon, and by a route that does not need map editing at all.
The password
That is on us. There is an “Set up with my iRobot account” option in the setup flow, and its description says “for newer models with no local setup, e.g. Combo” — which reads as not for you, when in fact it is the fallback for exactly your case: robot on the network, password not retrievable automatically.
So you did the right thing and the interface told you not to. The wording is wrong and I will fix it.
If it happens again on the second robot: pick that option rather than the external script. It signs in, fetches the password, and stores it the same way — the script you found does the same thing by hand.