It's perfectly possible to install those features without destroying the integrity of a house.
No, its not.
The house was designed without any of those things.
Installing any compromises the original design.
I think you're deliberately missing the point of what original features are. The whole thing with a feature is that it stands out amongst the less-special stuff.
A beautiful fireplace, oak panelling, a hand-crafted staircase etc. are all features that (you would think) most people choosing to buy a period house would want to preserve, but this doesn't mean that the space behind or underneath them was also designed as a specific feature.
Yes, it's nice to keep as much original as is feasible; but cutting a small, discreet channel into a normal part of the wall to instal wires or pipes is completely different from ripping out a beautiful, unique, fully functional hundreds-of-years-old door and replacing it with one of those nondescript grey ones that look like the entrance to an office block, that you see more now.
Carefully and sensitively adapting an old house so that it can be lived in with what are considered essential utilities now - such as electricity and running water - is a way of preserving its integrity in a way that keeps it in regular use. It's a careful balance of history and basic practicality.
Surely nobody is more meticulous about preserving the history and integrity of beautiful old period buildings than the National Trust - and every one of their stately homes, however old, has electricity and running water - designed to be in keeping and unobtrusive wherever possible. What they don't do is needlessly rip out an original walnut staircase and replace it with a pink plastic fireman's pole, just because somebody thinks it looks funkier.