This export in Tab.
Basically it creates the Geometry node called at the Scene level “file1”. Inside you'll find Surface Operator node called “file_xx” (looks like yellow folder). This is the same node we delete (as you usually see or will see in different tutorials) inside of the default “geo1” node (Scene level) before creating instead of the deleted - e.g. object node for modeling. The File Sop node that looks like yellow folder allows you to e.g. import as were talked about it .obj file > in the Parameters pane > Geometry File field > use Open Floating File Chooser - the next icon to the drop down menu icon.
Also “If its input is connected, you can choose a File Mode to control how the node reads, writes, or caches geometry on disk. If no input is connected, you can specify a geometry file to read in from disk and send through the node’s output.”
In Blender unit 0.01 = 1 cm.
Have only Houdini installed, but if you want to have your soldier imported into Houdini and have him human sized, I can suggest to create something like reference (e.g. box), to adjust its height to about for example 2 Houdini Default Units in Y and to resize then your character to the approximately same height. It will be more convenient - if to Ghost Other Objects (icon under the Viewport for Control visibility - looks like tiny sphere, tube and cone with drop down menu).
Do I have to resize my settings every time? After the exit, they are reset to 1 m.
As far as I know if you press Accept (not only Apply) - your settings will be saved as the default for this .hip file. Try to save your scene with new options and reopen Houdini. New default units should be in place.
All the same, the position 0 0 0 leaves after export.
You'll need to check it, cause I have only Houdini installed, and he reexports geometry to himself with changed values of e.g. Translate and not at the origin of the scene, but probably it's about finishing modeling chain of nodes with the null node, so it's usually treated as the good habit in modeling, and to export it out. Or maybe it's somehow connected with RMB > Make Current Value Default on a parameter you want not be changed of the last node for exporting, or with Lock Parameter.
Will wait if someone will answer this question/ these questions too.