As requested, here's an update. A bit sooner than planned and I was in a rush (work evening at the bonsai club today) so the pictures aren't great.
I have shortened the branches that ware far too long. The plant was repotted a year ago (back into its old plastic pot, unfortunately, as I broke the new one). The rest of the year I've left it alone and fertlized it heavily. I've let it blossom - but I did remove the flowers so it did not form apples, so the tree would not spend energy on that.
Seems that's working. On the second picture it's visible that there's a lot of backbudding going on, lower on the trunk, at the right places. As I write often, I'm not an expert, so it is very nice to see things do seem to work out as they're supposed to.
Not all flower buds are open yet, I'll try and make more and better pictures later.
Pictures of today:
