Great list with "standard" tools that you'd find on most systems by default. From my experience for virtualized servers you might also look at:

- system and stolen cpu to show virtualization overhead and VMs starvation for CPU (in vmstat)

- interrupts and context switches which might indicate that VMs might be running non-optimized OSs or non-paravirtualized drivers (vmstat)

- abusing VMs/Containers (platform specific), ie for KVM: virsh vcpuinf, virsh dominfo

- socket summary and dig from there: ss -s