I’m wondering what paths are available to upgrade from Alpha4 to RC.
The same question applies for the upcoming releases (from RC to next release; and to the releases after that) .
From this post I’m concluding that a fresh re-install will be required. I would hate to have to re-set all of the settings and re-find all my movies and tv-series episodes followed by setting the watched-state for each on every single upgrade. I’m kind of hoping that this will change in the future.
For our day-to-day-viewing-pleasure I’m still on RaspBMC because I find that OSMC (RC) is too unstable. I dont want to torture my family.
You’ve already discovered the answers to your points in the post you linked to, so I don’t need to re-iterate them.
Using raspbmc as a stable product is sensible from your point of view, as OSMC RC1 isn’t there yet.
If you have meaningful comment about lacks in RC1, it could be helpful to mention them (if not already covered by previous posters)
Derek
I was more hoping for some reassuring words regarding future releases. 
Yes of course. The whole idea with Debian APT packaging is to get a stable but also versatile install/upgrade/downgrade system.
Between Alpha4 and RC1 a lot regarding this was changed so a fresh install is needed between them.
This will not be the case for future versions.