Multiple subnets on VMware host

vSphere doesn't forward packets like a switch does, so it cannot create a loop (unless a VM on that vSwitch forwards them). I have many vSphere hosts connected to two stacked Cisco switches and it works fine (both with some form of etherchannel and built-in VMWare failover).

My reading of that article is that you should enable PortFast and leave bpduguard enabled. The VMware vSwitches pay no attention to the BPDU\STP traffic but it's possible that something could be done in a multihomed guest spanning separate vSwitches that could cause issues that bpduguard might help mitigate. It's far more likely that (re)wiring issues will cause trouble and having portfast+bpduguard in place will prevent a lot of the trouble that can arise when someone gets it into their head that they need to rearrange some cabling.

So enable bpduguard globally, use PortFast for the VMware uplinks (and another port where pure STP might cause problems) and you should be well set up.