As you say, both are debatable issues - but, as you also imply, it's a pretty common arrangement.
As for (1), the same could theoretically be said of the switch (albeit {probably} not the terminals) of a switched socket - not to mention the fact that appreciable currents in excess of the load on the socket (limited by plug fuses) should not flow through the material of the terminal. In the OP's case, current though each of the switches is limited by the associated fuse, so the only possible issue is the switch terminals.
Your (2) might occasionally be a theoretical issue, although, as often said, the same would be virtually as true of a row of adjacent sockets or FCUs on a ring. In any event, in the OP's case, the loads in question (fridge, extractor fan and DW) could never overload cable of ≥20A CCC, no matter how close they were to one end of the ring.
As you have implied, I very much doubt that the OP would get anywhere in arguing about the above two issues which, at the very least, are matters of opinion/interpretation.
Kind Regards, John
