MSMQ can be placed on the Systemdrive (C:\ usually). Unless you have a very high archving rate, then put them on a small disk. I would definitely not have VSP's on the same drive as the Indexes, due to i/o restraints. I obviously do not know your storage solution, but what you can do if you use CIFS shares/Networkdrives for the VSP's, is to map those to an empty folder on a small disk. Create a folder called VaultStorePartitions, then subfolders Partition1, Partition2 etc. Mount the respective CIFS/Networkdrives in each folder.
As for the legacy indexes, these most likely will provide search only, so I would try the same solution as for the VSP's.
There is documentation available which will assist in moving VSP/Indexlocations if necessary.