Question about Nanoleaf Shapes Hexagons Starter Kit (15x)

Answer 1: Yes, you can connect the triangular ones with the quadrangular ones as well as with the hexagonal ones.

2nd answer: It does not matter where the 2nd power supply is connected. And no, you don't need a separate 2nd starter kit, just a 2nd power supply. (Don't know if a power supply is available separately).