Buffalo SNES Controllers and keyboard configuration messed up..... :-|

SutterKane

Hello.

I am a little bit confused about keyboard and controller configuration on the Retropie (latest version) on an RaspberryPie Rev.3 Maybe you can help me out.
Connected are a wireless keyboard (via a dongle on the USB Port) and two Buffalo SNES Controllers.

The configuration of the controller have been done in Emulations station (several times) and I can move in the mainscreen after the Pie has booted up perfectly with the Bufffalo SNES controllers (left, right,up, down, selection with Button A).
If I start a game, the controllers are mentioned shortly in the lower left corner in yellow letters, as it has to be.

Funny thing (but not the major issue) is, that after the game has started button A and B are exchanged (e.g. while playing Mario Kart).

What is confusing me: While trying to play MAME games, the controls are totally messed up.
E.g. Fire is on button Y, movement can just be done into two of four directions

My questions are here:

Is it possible to activate the keyboard also for moving and games selection in the main menu of Emulationstaion ?
At the moment, the keyboard is totally ignored, but e.g. when choosing the RetroPie setup from the main menu, the keyboard is working without any issues in the "Text-GUI", where you can manage packages and all this...
Playing games via MAME (and other emulators): Is there an additional setup to be done to get the Buffalo SNES controllers
working correctly ?

Aaaand in attrac mode:

Game selection via the controllers is just working downwards in the main menu, the "Up" key is totally ignored. Starting a game via the controllers is possibe (and the game starts perfectly) but no controlling is possible as described above (2 of 4 directions).

Have the controllers being set up for any Emulator/Mame separately ? Andi f so : How/Where exactly ?
Is there also a special controller configuration for attrac mode ?

Thank you for helping me out.

SK