Hi Glenn;
1) The DisableBind workaround might be a lot easier to implement if your PB application(s) just used a 2nd Transaction Object for just the RTE updating (food for thought until SAP/Appeon can fix this 
).
2) Q: I am curious about you comment about nvarchar - generally we need that to support international languages - what experiences to do have with character remapping with that?
A: We only support French and English here in the Canadian Government as these are the only two official languages of Canada. However, at the Department of Foriegn Affairs where applications roll out to Embassies - we use nChar & nVarChar as other languages other than those two are supported.
3) would love a more detailed separate discussion about that.
A: Indeed .. I would suggest opening up a new discussion thread on this aspect as its quite an intriguing subject.
4) may be a serious bug affecting everyone's data.
Yes, SAP should have treated this more seriously IMHO.
Hopefully, Appeon will go to public betas as well for their PB releases ...
which will allow us to find & fix these type these of things before GA!
Regards ... Chris