It takes 2 units to create a point-to-point connection (radio link). Use as a point-to-multipoint is therefore possible with several units, and can also be used as an access point but makes less sense (see User Guide or Quick Start Guide).
It can be used in Switzerland without a licence (free band, without concession). Attention must be set to "Switzerland" during setup (power is limited and so are certain channels).
Sorry, no idea if it needs a licence in Switzerland. No, it does not need a receiver. It simply amplifies a PRESENT WLAN (in a certain direction). But I don't find the amplification very clear.