Kerbal Space Program

Kerbal Space Program - 1.0.5.0 (LinuxPlayer) Steam
Linux betty 3.16.0-60-generic #80~14.04.1-Ubuntu SMP Wed Jan 20 13:37:48 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux
Ubuntu 14.04 LTS

Subject: Steam API seems to be broken

Description:
1) Steam Controller config (default or custom) is not applied. E.g. the right bumper button always brings up Ubuntu's left-alt key menu.
2) The Steam overlay does not function, with KSP running either in full-screen or non-full-screen modes.

Steps to replicate:
1) Install KSP with Steam on platform as specified above.
2) Test Steam Overlay and Steam Controller functionality is correct in other (not KSP) game.
3) Attempt to use Steam Controller in game of KSP.
4) Attempt to use Steam Overlay in KSP with left-shift+tab keys.

Expected:
1) Steam Controller functions with default or custom configurations.
2) The right bumper button of the Steam Controller does not trigger the left-alt key menu in Ubuntu Unity UI when running KSP.
3) The Steam Overlay appears when left-shift+tab is pressed in KSP.

Notes:
1) This might be considered a duplicate of #5996, but is more expansive in that I describe how the Steam Overlay does not function in addition to support for the Steam Controller being broken.
2) The Steam Controller itself seems to be detected by KSP, as the KSP UI shows info on the Steam Controller mode on the launchpad, etc. Evidence in the logs supports this too.
3) As described in bug #5996, the root cause of the problem seems to be this line from the Player.log ...

Fallback handler could not load library /home/darren/.steam/SteamApps/common/Kerbal Space Program/KSP_Data/Mono/x86_64/CSteamworks

4) As with the comments in #5996, I have tried copying the bunch of .so and .dll files into KSP_Data\Mono\x86_64 and have tried both symlinking and copying/renaming (on separate occasions) libCSteamworks.so and CSteamworks.dll to have the name "CSteamworks" as per the error line quoted from Player.log above, to no avail. Nothing I do affects the existence of such lines in the Player.log or the 2 effects of this bug as described above.
5) The Steam Overlay and Steam Controller operate as expected in other games.
6) Deleting local KSP content in Steam and then nuking (rm -rf) the top level KSP directory, re-installing and retrying makes no difference.

Thoughts:
1) Despite the commentary in #5996, I'm still not sure whether .so or .dll files are actually required for these features on Linux.
2) There is no file called simply "CSteamworks".

Files added::
1) Player.log
2) KSP.log

Steam Controller Config:
My custom Steam Controller Config is public and is called "Fnordianslip's Linux config". It simply changes the right grip button to right-shift from left-alt for all use-cases.