Questions about Lenovo USB 3.0 to

Yes, you can, but you could also just use a small USB dock that has a LAN port and a monitor port. That might be better, as it usually gives you a few extra USB ports. I would use something like that, for example: Value USB Type C (1 x HDMI, USB A)

was sind 100 mgbits? https://www.lenovo.com/de/de/accessories-and-monitors/cables-and-adapters/adapters/CABLE-BO-USB-3-0-to-Ethernet/p/4X90S91830

Unfortunately, I only work at Windwos level.

The answer is no :)

Yes, that is an active adapter, automatically recognized by Windows and Linux. No additional drivers required.

The adapter should be compatible with the Lenovo Yoga 700-14ISK.

Yes, with this adapter a yoga 3 (also other notebooks with USB 3.0) can be connected to the LAN via cable.