If you laptops support MST extend mode, then yes, but most windows support max 2 monitors extended, mac OS only support mirror and non-mirror mode, non-mirror mode shows 3 same monitors but differ from the laptop.
Yes. It can. When mounting power-hungry devices ( such as power need is more than 1.5A SSD or HDD ) through the USB3.0 port, an external PD( USB-C) power adapter is recommended to be used, so that the external hard drive can work properly.
It will not charge a laptop unless you plug in a type-c charging adapter to type-c PD port. There are 2 type-c female ports, one is for PD charging ( 20V/5A), the other is for data transmission ( 5Gbps ).