If you want to monitor your servers you need the System Management Homepage for viewing the page also this piece of software has has Open SSL security issues. The Version Control Agent is not needed for monitoring, i would suggest uninstalling the software since HP is moving away from VCA in favour of HP SUM.
Snmp agents and/or wbem agents need to be a recent version due to new hardware support and for compatibility with SIM for reading the system info and traps. If you don't have newer hardware you could use older SNMP and/or wbem agent but why do that? The drivers and firmware you can skip but if you run into support issues the first thing HP is going to say is update your drivers/utilities. So the last option is where you will face downtime so that would be the only reason not to do this.