I believe it's better to report each one, but reporting a combined.

1. problem one
pkg move of kde-apps/oxygen-icons to kde-frameworks/oxygen-icons happened.
https://gitweb.gentoo.org/repo/gentoo.git/commit/profiles/updates/4Q-2015?id=b9db3a043ecd2585f5bbcc9d28362e7fab44fdac
this move present in ports-2012.
Connected to this move kde4-base.eclass changed to have dependencies of kde-frameworks/oxygen-icons
https://gitweb.gentoo.org/repo/gentoo.git/commit/eclass/kde4-base.eclass?id=b9db3a043ecd2585f5bbcc9d28362e7fab44fdac

This change present in kde-shard only and not yet hit ports-2012:
http://git.funtoo.org/gentoo-kde-shard/diff/eclass/kde4-base.eclass?id=e99d42e21e51066725ab87919ef73ef260f9f24d
A side effect of this is that kde-frameworks move occured but ebuilds prefer kde-apps/oxygen-icons dependency at same time and giving file collision between kde-apps/oxygen-icons and kde-frameworks/oxygen-icons. build.log attached.

2 problem two:
kde-apps/kuser-15.08.02 does not build with dev-utils/cmake-3.4.0. It's fixed with kuser-15.08.3 and present in kde-shard, not present in ports-2012.

3. problem three:
merging of kde-framewors/oxygen-icons wants deps, which is not yet in ports-2012:

# emerge kde-frameworks/oxygen-icons
Calculating dependencies... done!
 
emerge: there are no ebuilds to satisfy ">=kde-frameworks/extra-cmake-modules-5.16".
(dependency required by "kde-frameworks/oxygen-icons-5.16.0::gentoo" [ebuild])
(dependency required by "kde-frameworks/oxygen-icons" [argument])

it's ok in kde-shard.
4. problem four:
funtoo-overlay has kde4-functions forked,it was necessary to fork when progress had copy of this eclass, with issues. No longer require to have a fork