I agree with you entirely. I would like to see the U.K. abandon the ring circuit completely and move toward using radials. The Regs. today still provide for 20 or 30/32A radial circuits, serving limited floor areas.
If we could get dedicated circuits for major appliances -- as you say, the washing machine, dryer, dishwasher, etc. -- then a few 15/16A or 20A radial circuits would be ample for the rest of the house. It might be a good idea to specify one or more such circuits specifically for general-purpose outlets in the kitchen area, as does the American NEC.
As for lighting, I think most of you in Continental Europe combine lights and receptacles on the same 15 or 16A branches, don't you? (I know France is the main exception to this as they seem to use separate 10A lighting circuits.)
Although 5A lighting circuits are the norm for residential wiring in England, the Regs. actually allow standard BC lampholders to be connected on any circuit up to 16A, so if radial receptacle circuits were set at that level then I don't see a problem with incorporating lighting on the same circuits. (I'm assuming that you do this in Sweden, right?)
The main RCD employed in houses with TT earthing systems here is something I don't like, for the reasons you've mentioned. One ground fault anywhere in the house and you're plunged into total darkness.
I too would like to see RCD/GFI protection split to a per-circuit basis, although as you hinted, with the cost of combined breakers as they stand at present it would get very expensive. (I'm sure costs would drop as production increased if individual RCDs became more widely accepted.)
By the way, although GFI receptacles are quite common in the States they do use individual GFI breakers at the main distribution panel as well (and I don't think the new AFCI types are available in receptacle versions yet either).
