1. It should be possible, if not maybe your system isn't correctly maintained in LMDB - did you run verification?
2. For ESS/MSS, you need a J2EE portal system which connects to your ERP.
3. You have to select the upgrade option and choose the correct usage type for HR / HCM.
4. EA-HR 607 and LSOFE 607 can only be applied in a EhP7 system.
If you need further assistance let me know.