Hi Else and welcome, I thought I'd chip in as an ex Essex man myself...We used to live in Nounsley near Hatfield Peverel before we upped sticks and came out here about 20 years ago now.
After catching up on what you have been trying, you've made progress, well done. I will only add that having been through similar trials myself and also being a relative newcomer to these venerable old machines I have found my A10 runs and starts better on standard low octane unleaded, rubbish 91 ron here, but it seems to like it so give that a go certainly no more than 95 ron unless you are running high compression?
We are lucky here in Aus in that we can still get fuel without ethanol in it but whatever you use keep this down to a minimum as it won't do you any favours.
I always give her a tickle first thing in the morning then I get the bike out of the shed...etc.etc. but all joking apart my bike here in Aus doesn't even have a choke fitted but it does like being flooded to start, by which I mean depress the tickler until fuel just appears to wet your finger. (you can overdo it). Then I slowly ease it over a couple of revs until at least one cylinder is just over compression (actually good practice at this point to pull the clutch in and kick through to clear the plates then give it a hefty swing while cracking the throttle about a 1/4 open and it generally fires immediately, it'll then settle to a rather slow tickover but I generally keep it running at a fast idle on the twist grip while it warms up a little.
I've not tried the Brisk plugs but have had no problems with NGK BP7ES just make sure they are genuine ones! (mine has an alloy head)
Good luck with the brakes, I've tried everything and there's plenty of info on here. (use the search) Progress has been made but they still only just slow me down rather than stop me if you know what I mean! Be careful about following any modern motors or motorcycles for that matter there is no stopping if they anchor on hard...
Wishing you all the best with the new bike it looks lovely.