Happy to reply. : ) A W window should be fine. As close to it as possible.
The dark spot looks necrotic to me.
I don't consider what I described as drastic, just regualr maintenance. There's no way for a Kal like this to stay straight over winter unless it right next to a window, so I do that to all of mine in the spring. Since discovering they will still bloom, just in a floppy manner, if not right by the window, other plants have taken precedence and the little trees are no longer practical. They end up looking like the asked-about plant, with branches dangling down.
Here's an example from 2 weeks ago. This is the day I took the mama plant outside and these are the tops I cut off and stuck in a new pot. It looks exactly the same today except that the blooms are slightly more upright from being back outside for the past 2 weeks.
When I've kept individuals alive for a few years, I end up with these if they are right by a sunny window. Interesting but since they'll bloom in less light than required to maintain upright-ness, I don't want to devote the height-space to this kind of plant anymore. Nothing wrong with it, if space right by a window was unlimited.