re Kent: I quite like this (on the understanding that is accompanied by the appropriate number of list seats). In terms of communities I think this makes a lot more sense than any recent configuration in Kent. Romney Marsh was of course always part of the Ashford constituency back in its earliest history and I personally am not opposed to Hythe splitting from Folkestone. The pretty enormous Kent Weald constituency (which is where I personally would finish up) still does look like the "bits left over" one, but is a lot more coherent than a number of versions we have had to endure in the recent past -the people in the M20/A20 corridor like Charing and Lenham would probably say they weren't Weald they're Downland, but its arguable. You seem to have created an eminently winnable Lib Dem target in Maidstone which would probably delight my Maidstone LD colleagues.It's probably right that Ashford constituency is kept a bit on the low side as it will catch up fast. I like the single Thanet seat, and the elongated north-south constituencies in West Kent (Sevenoaks, Tonbridge) are no odder than what has happened there in the past.
Then I want 6 All-County list seats to go with these 12 constituencies! On the basis of a national electoral scene much as now that would probably give the Lib Dems 2 seats (Maidstone + 1 county list), Labour 3-4 seats ( Canterbury+ one possible other -perhaps Dover/Folk?,+2 list seats) and the Tories the rest 9/10 constituencies and 3 list seats. Of course a new system, together with changing events,might mean people voted quite differently.
I wouldn't get too carried away about Maidstone - the Lib Dems have never matched their local election strength there when it comes to general elections. Maidstone was one of those seats where the Lib Dems held up relatively well in 2015 but they then collapsed in 2017 to 16% of the vote - and that's the good news for them. In Faversham & Mid Kent and Chatham & Aylesford which provide the rest of the seat they got a derisory vote, I know the LDs used to get a very good local election vote in the Aylesford/Larkfield/Ditton area but it never counted for much in generals and doesn't count for much in locals anymore either, so I'd stick to relying on the list seats. Also Labour wouldn't win Canterbury with Herne Bay included
I understand what you are saying -and why- but I am nothing like as "pessimistic" as you about Lib Dems in Maidstone or Labour in Canterbury as you are, because the targeting would be so different with a different set of boundaries. I think the Lib Dems in Maidstone would be a very different proposition without having to worry about a large chunk of very blue Weald, and Herne Bay has never really been worked hard by anyone IMO
Labour could have worked their arses off in Herne Bay in 2017 and they would not have got within 200 votes of the Conservatives which would have been necessary for them in order to have won Canterbury on these boundaries (if you're thinking of furture elections, bare in mind that the Conservatives didn't do any work in Canterbury at all as they imagined it to be safe). There's an obvious limit to how much effect work can have because some voters will just not be open to voting for you (that's undoubtedly more true for Conservatives and Labour than for the Lib Dems but there is also a limit to what you can do - I get way more attention from the Lib Dems in terms of canvassing and leafleting than I do from the other parties but I'll let you into a secret - I'm not going to vote for them)
Once you have agreed that the system is AM list top up, why does the +/- have to be so tight?
+/-10% is pretty generous. I have not ordained anything besides 435 seats, +/-10%, a certain number of seats per review area, and protected seats for the Isle of Wight and two separate island chains in Scotland. But there's some importance in a UK-wide quota. And there exists some merit in a uniform upper limit and lower limit, though this could be overridden if such a strong need existed. It is unfortunate that sections of Scotland might have* be such a mess with such rules; I am unsure how to avoid it though. Perhaps give it a bigger band? Say, +/-15%? While leaving the rules unchanged in all other respects? Maybe this could be twinned with provision for there to be allowed a set number of constituencies that could be permitted to fit an even looser threshold? *=looking at it, the math in the Highlands make its hard to work with...but I am unsure if it's unavoidable.
103154 is the quota, so 20% makes for 82523-123785. I would also make provision for a looser, special 25% band in use in the Highlands council area.
This is to allow for this, which seems to be the ideal arrangement in the Highlands. And it might be justifiable thanks to how remote the region is - the population density in the Highlands rivals that of portions of Siberia.
Certainly there must be a reason why the island constituencies have been protected in successive legislation passed by the Government, and (as far as I know) have never had a seat in common with the mainland. If it was a dozen island constituencies off the coast that were massively under quota, then we'd have a problem. But there's only 2 of them.