Regarding Mer, it would be good to have a structure with top Mer section, and specific subsections (Nemo, Sailfish and PlasmaActive for now).

At least if the forum allows such thing. Since some topics can be Mer generic (like for example adding community repositories and libraries), while others will be OS specific (like ironing out issues in each particular OS).

I basically outlined my proposal above, so repeating it here. In addition to existing Maemo and Harmattan sections, add these:

-> Systems
-->> Mer
--->>> Sailfish
--->>> Nemo Mobile
--->>> Plasma Active
-->> Ubuntu Mobile
-->> Other
...
If that's not possible, and the forum supports only one level of hierarchy, then something like this would make sense:


-> Systems
-->> Mer
-->> Sailfish
-->> Nemo Mobile
-->> Plasma Active
-->> Ubuntu Mobile
-->> Other
...

NOTES:

It's probably better to call the section Ubuntu Mobile as a collective name, since they have now a whole bunch of projects like Ubuntu for Android, Ubuntu for tablets and Ubuntu for phones, and they aren't all the same, so Ubuntu Phone would be too limiting.

Making "Other" section would accommodate for other potential systems of interest (which can even be created tomorrow), and if they'll generate enough activity on their own, they always can be moved to a newly created section. Names like "Competitors" don't make anymore sense in this context IMHO.

As jalyst pointed out - this proposal is not related to any domain name change - it's a separate issue.