Does this hub support display transmission?

No, the 4 USB C ports on the side of the product only support data transfer, not support for powering peripherals and compatible displays.

When l connect all 4 USB-Cports, why can't I reach 10Gbps?

When we connect only one USB-C port, the maximum speed (10Gbps) can be achieved, but when connecting multiple USB-C ports, the bandwidth will be automatically allocated, so less than 10Gbps.

Can l charge my laptop via any USB-C port?

Yes. Through the USB C PD interface at the bottom of the product, it supports a maximum of 100W power supply, and the power supply is in one-way mode: Power adapter---Hub---Computer.

Can the product support connecting a USB-C to J45 adapter?