I guess really I was hoping to see if somebody could tell me if it was a bodge, and if so to what degree.
Hole in the top of the CU
That connector block and the blue wires should be inside the CU or some other enclosure, and what exactly it is for is a mystery. Should not exist on any new installation, appears someone has just used it for a neutral.
The other conductors in the cable have been cut off - they should have been connected to earth if they are not required.
CU is a typical DIY shed effort, shoved in with no thought whatsoever.
Very few circuits, the absolute minimum.
There is no cooker circuit which will be a problem if you want an electric hob or double oven.
Old fusebox left in place although presumably disconnected (the beige item with the conduits to the right).
1/2 a blank missing from the front of the CU and the internals are not aligned properly - small space to the left of the red switch should not be there, neither should the tiny gap between the 'sockets' and 'lighting' MCBs. The whole lot needs moving to the left, and where the 3 small blanks are next to the 2nd RCD should then be 4 small or 2 large so there is no gap.
As for normal - sadly there are plenty of installations like that.
Under the sink - another typical mess.
Socket has a big hole in the top which should be sealed, or cables enter from the bottom/side.
The socket being under the sink is not a problem.
Green hose and jubilee clip is rather suspect, the sort of thing that could be forced off under pressure and cause a massive flood.
The white flexi hose is either because someone obtained the wrong trap for the 2 bowl sink, or it's from Ikea. Either way needs to be replaced as it will be constantly blocked and impossible to clean.
The rest of the plumbing is of a poor standard, pipes unsupported, the braided flexi hoses can and often do burst, and that carrier bag holder at the back right is designed to be fixed to a wall, not shoved into a cupboard.
All of it is exactly what you would expect from people who have no idea what they are doing and don't care either.