After couple of years and many ideas, I have finally settled on a design for my experimenter's board.
Say hello to EduKit BoosterPack.
The EduKit BP comes with 1.8" color LCD and 8 accessory connectors. Each connector provides access to power and 2 or 4 MCU pins and are used to connect accessory boards. Those boards will allow user to perform tests and experiments, and could be used to teach about MCU's. There are also 4 jumpers on the board, which are used to change LCD's connections. LCD can use SPI1 (UCA0) or SPI2 (UCB0,) CS and D/C have also 2 possible connection options.