Belatedly, some comments.
I support using Debian, and Jessie (stable). I also think that LXDE and Mate are the best choices for R9.
On installers : if still researching, Tanglu distro is product of some Debian developers, and their recent release has a new debian-installer (avoid, as they recommend, the live installer)
I'd like to think that anyone without a separate /home partition has a backup strategy, and hence there's no critical need for a rolling upgrade.
My view is that the iso should focus on getting the distro installed. Applications can come later, via synaptic or custom menu items/desktop icons covering key areas such as optional multimedia (players, codecs, ..) and optional "big" applications (Thunderbird, LibreOffice, Gimp). Where practicable, issues on Broadcom and nVidia should be addressed in preference to adding more applications IMO, and the basic install should permit new users to report the sort of detail support people ask for ... (so : inxi and/or hardinfo and/or ....).
I suggest Pale Moon as browser - lighter, not bleeding edge, essentially Firefox.
If feasible, I suggest that the default (but not only choice) config for users who choose to install on "full disk" should feature a separate /home partition. This approach makes later upgrades, and interim backups, more manageable and less risky. Only the smallest HDDs would be an issue.
microwatt has been a goal from waaay back, and I can understand your disappointment that it hasn't gone smoothly. I also understand the 64-bit version being first to be dropped - as I recall, microwatt was to be an even lower demand on resources than mainstream wattOS for those who could manage without the more elaborate desktops, fitting in with the notions of lower power, less resource wastage, keeping computers viable while reasonably practical. A stripped-down rocketship on a 64-bit platform with modern cpu and heaps of RAM is a different concept - fun, but different. IMO, of course. :-)