Appletrees, I agree with most of what you are saying, but with a few caveats:
If your topic is Romans and you are embedding everything (literacy, numeracy etc.) into that topic, then of course in a piece of writing spelling should be very important. However, so should structure (i.e. beginning, middle, end), richness of language (use of connective, adverbs/adjectives) and creativity in terms of plotting. All those features will encourage a child to achieve where it matters later on in their school life, so if those elements are there early on, they should be acknowledged.
I do worry that environment is a really big factor and I don't have a quick fix - and it is unfair to expect state schools to pick up after parents who can't manage the basics of toileting, conversation and socialisation. My girls' school has a very, very mixed intake and some of the parents have to be seen to be believed - if they are feral, how can their children not be? Would your proposed school fix this, and if so how?
Lastly, I do agree that some old-fashioned methods work. Both my DDs are in state schools which use such methods - learning by rote, if handled well, is a useful tool. DD1 is learning mental maths, finding it both a struggle and a challenge, but she understands the need for it and every week that we go shopping together I can tell her to the nearest £3 what our shopping is going to cost. She has taken to looking at the receipt and has started checking it for mistakes, bless her! No refunds yet, though
. I'm annoyed that her school (and schools generally) in the UK don't seem to want to extend the rote learning to the learning of foreign languages though. DD is learning French, but it all seems to be phrasebook stuff - no-one is teaching her French grammar, irregular verbs or anything, there's none of the stuff I did at school so she can't build on the vocab that she has - the structure just isn't there. Well, perhaps I'll have to do it myself...