If you click the add-on buttons, that will often change the symbol filters. The fastest way to go back to the default settings is to re-open the map, since this loads the settings again. And the quickest way to do this is just to first hit save, then pick the top option from the recent map files at the bottom of the file menu (the current map should be the top one)

You can also open more than one window in CC3+, and these can have different zooms. They don't offer different rotations, and they will have the same set of sheets visible, you you can't hide a sheet in just one of the windows.

You find this under View -> Windows

While there are tools to help you easily/automatically draw a city, there isn't a way to automate the drawing of the walls. A normal city is seen from above, so you see what you refer to as the roof drawing.

But for making the "interior" view, you will need to draw the walls/windows yourselves. The house symbols doesn't have removable roofs that reveal readily-made interior. It is easy enough in CC3+ to hide the roofs (or more accurately, hide the building symbols) to reveal what's beneath, but you will need to draw that beneath part yourself, otherwise you would just stare at a blank area.

I guess you could use the automatic floorplan generation to help you with this. When you generate a floor plan from a house (only works with proper CD3 symbols), a separate drawing is created with the walls of that building. Those walls could then be copied back to the main city drawing and placed under the house so that they are revealed when hiding the house. It will be some manual work doing this, but it at least gives you the building outline for free

Seems like there is a bug with the template. I'll notify the appropriate people, but as a workaround you'll need to modify them manually in the fill style dialog. There isn't a global setting for this.

🎬️ Videos: Fixing Selection

At times you may find that selections doesn't work properly. For example a command that expects you to select something (such as the erase command) just seem to terminate without allowing you to selecting things at all, or it might appear to select things automatically.

This is caused by the fact that CC3+ has different selection methods for different purposes, and sometimes the wrong one may be enabled (often caused by a macro that didn't complete properly).

To fix it, select Options from the Tools menu, then hit the Select method button and make sure that the selection method is set to "dialog or Popup". Make sure to just hit OK to exit out of the dialogs, and your selections should work as before.

If you don't mind using the CC3+ command line, this can also be fixed by just typing SELBYD followed by enter.

?️ Further Reading: Selections