Additionally, if I were instead to buy a USB-C hub with a built in MST hub, should I be able to run KVM through the one USB-C port, I am aware it has USB2.0 but I am unsure if this is a good idea. I will definitely be using the separate NIC and USB ports for file transfers though ^^
This way I can have a pseudo-docking setup with three monitors, and only one port required (I am ignoring charging for now)
That dongle should work, however the specs indicate that it is limited to DisplayPort 1.2 which has lower bandwidth and worse features than newer DisplayPort versions.
Instead I suggest this dongle as it supports a newer standard and also has USB ports (and an Ethernet port limited to 480 Mbps as well as a charging port, although the charging port won’t work for charging the laptop): https://www.amazon.co.uk/dp/B085VLPYDR
Yes that should work, however beware that many of those hubs will take away bandwidth from DisplayPort and try to allocate it to USB 3.0 bandwidth (which ends up just wasting the bandwidth as the port doesn’t support USB 3.0). The hub I linked above doesn’t do that and allows full bandwidth to DisplayPort (which helps ensure your displays can run at full quality).