How specifically do you "Using the template from ONE of them (in PTGui) all three resp. 5 stitches provide pefectly lay-overs without needing to find and set CPs for the other shoots." - I find the instructions for making and applying the template unclear.
Thank you for your time!
In brief - i´m in very much a hurry:
"2.13. What does 'Apply Template' do?
This copies the settings of another project to the current project, except for the images and the control points. This function is accessible both from the 'Apply Template' item in the File menu, and from the toolbar in PTGui. A template can be any PTGui project. In Tools/Options/Folders&Files, a folder can be configured where you store your templates (on Mac go to the PTGui menu, Preferences, Folders&Files). Then, the template selection dialog will by default open in this folder. There's a little triangle button next to the 'Apply Template' button on the toolbar, which shows a drop down list of all templates in the configured template directory, for quick access.
Templates can be useful for a quick initialization of a project (lens settings, rough alignment of images), although this is usually not necessary since the Project Assistant can figure out the alignment of the panorama by itself. Another use for templates is when you have an exact reproducable setup (high quality panoramic head with fixed angles). In this case you could copy all settings of a previous project and there would be no need for placing control points and optimizing.
By default, applying a template copies all settings from the template to the current project except for the source images and the control points. In PTGui Pro this behaviour can be modified in the Project Settings tab, section 'template behaviour'.
2.14. Apply Template does not copy the control points from the template. Why is that?
By default applying a template copies all settings from the template except for the actual source images and the control points (see Q2.13). Control points are never copied since they are specific to the source images. For example a control point could originally point to the corner of a building in the template project, but in another project the same coordinates may be in the middle of plain blue sky. In other words the control points are meaningless outside the context of the original images.
If you just need a project to be stitched exactly like the template project, control points are not needed at all. Control points are only used by the optimizer to determine the best image parameters. The stitcher then only uses the image parameters, not the control points. Therefore it's sufficient to apply the template and proceed straight to Create Panorama without running the optimizer."
Source: PTGui FAQ.