Adobe and B&N addresses are unrelated (except with NOOKstudy). There is no need to fuss with Adobe.
To change your B&N e-mail address:
- Put your B&N account back to the address/password NOOK is registered with.
- Unregister your NOOK.
- Change the B&N account to the address/password that you want.
- Reregister your NOOK.