Is this possible?

Correct. You would receive the maximum of 70 units towards the graduation unit requirements. The remaining surplus would be used as “subject credit” where you don’t have to retake the classes, but they won’t add towards the graduation unit requirements.

All CCC courses are lower division.

Yes as long as you don’t take any 300+ level courses at UNR or any other 4 year institution.

Also, I completely agree with @briank82 in that the only foolproof way to get your residency change approved will probably involve taking a gap year and not taking any classes – even from DeAnza.