Cat5e for motion/presence sensors if you plan any.

They will be just fine at 0.

homelab and homeservices should be 2 different things and separated as much as possible but can share some like a network. Not sure why you to trace where connected where, use UniFi network diagram and some IPAM solution to track VLANS an IP addresses.

servers only, managed routers and switches are just miniPC by themselves (mostly not x86, but mips/arm).

iDRAC is just miniPC with access to the server hardware. You can plug that PC in whatever network or use VLAN. In datacenter/corporate infa they are connected to the separated network with very limited access to it.

Lucky you, I have only 7910/730…

Internal/managment staff - via WireGuard or other VPN

Services - via proxy and custome dns, like Ngnix proxy manager.