1) Difference between standalone converter vs Vcenter Converter?
They both function in the same way. The big difference is one is a plugin (vCenter Enteprise Converer Plugin) and the other is standalone.
2) Difference between host update utility vs Vcenter Update utility?
Host update utility is no longer available in 4.1, but is/was used as a standalone patching tool for ESX(i). Don't know of a vCenter Update utility.
