What do you generally think of the offer and the build quality of the wall and roof? Is it conceivable to leave the house as it is and in the next few years only renew the windows, roof EPDM membrane (possibly additional insulation), and the heating system, but otherwise apart from the usual painting/flooring no major renovations, especially no core renovation?
The electrical installation should run in empty conduits, I think, so easy to replace if needed. All water pipes run straight vertically through the basement ceiling and should also be very easy to replace.
You write that no glass wool is contained. As far as I know, in the 70s mineral wool was also called Baufilz. In the mentioned areas in the roof and wall it would also make sense, or it could theoretically be based on something else, but I would bet with high probability on that. That is initially not a fatal flaw, but it can sag, downward in the wall and also in the ceiling between floors it can be flatter after 50 years than before.
Typically, the damage pattern is then mold formation/damp spots on exterior walls under the ceiling. In most cases, however, it will be where it belongs.
In this wall structure, it is also clamped in front and back, so sagging is hardly possible.
The electrical wiring will certainly not run in empty conduits, at least that was not standard back then.
If separate fuses and RCDs are installed, but that is also not a big deal.
The water and sewage pipes should be replaceable without problems in the basement.
I would calculate replacing the oil heating system (with a heat pump).
Possibly insulate the basement ceiling.
Replacing windows makes sense.
Generally, if there is no odor nuisance/positive pollutant measurement and no visible moisture damage, from a distance and unseen this is initially feasible.