To connect both sides you need to try load delivered custom settings. Keep all components for adjustment : If you set the poses policy to “keep” or “adjust within tolerance” this preset allows you to keep all the photos, even if they actually are several…

It's been explained to me that 2.5D refers to a terrain that has z data for the ground elevations but won't allow you to go to a higher Z to represent items above ground.

The breaklines are in a cell, if you drop it you should be able to add the breaklines to your terrain. I noticed that the file was saved with OpenRoads Designer 10.07.01.32, this version has some defects and I'd recommend to install the last one, 10…

A terrain Model (I used the word element above - as it is a MicroStation element) is not equal to a STM. They are different element types - you cannot add breaklines to a STM.