Hello Alex,
1) Yes.
2) The difference is described in the release notes of SP3. Usually higher SP levels offer new functionality, compatibility, etc. Furthermore we have to note that the development teams provide the patches for the latest minus ~3 SP levels. Example: An issue is discovered in SP5 and reported by a customer. The latest SP level is SP9. The development team identifies the issue and if it is new, they provide a fix for SP5 and write patches for SP7, SP8, SP9. As you can see SP6 will not have a patch for this particular issue.
This case is simpler, since all SPs have this fix:
- SP2 and SP3 have this fix by default.
- SP0 and SP1 has to be patched to have this fix.
Best Regards,
Peter