The eave line you show is the roof pivot line (or pitching line).
It is a non-printing line that does not show on the layouts.
It can be controlled in plan also via the 'On-screen Display Options' - it can be turned on or off.
It will always show when you select the roof to edit it regardless of the on-screen options.
The options you show for the dimensions only work when you click on the side of a wall to place the dimension.
Click once on the side of the wall when placing a dimension and it will add nodes for the outer edges, core edges and/or reference line if you have those options selected.
It has no effect if you are picking individual nodes at the ends of walls because Archicad assumes you want just that node.
One of the forum moderators.
Versions 6.5 to 25
Dell XPS- i7-6700 @ 3.4Ghz, 16GB ram, GeForce GTX 960 (2GB), Windows 10
Dell Precision 3510 - i7 6820HQ @ 2.70GHz, 16GB RAM, AMD FirePro W5130M, Windows 10