Help with Honeymoon planning?
 

I'm kind of overwhelmed with the options listed in these forum pages, especially when looking at the advanced routing codes. I could use some help.

We would like to fly out on June 13th or later (flexible), MFR-France. I say France because we're open to options. Hoping for around 8 days in France, but would like to tack on a few days in NYC if possibly. Thing is, every option I see makes NYC look quite expensive for us. Best prices seem to be MFR-CDG vie KEF.

Interests
1) If we fly through KEF, worth it to stay overnight before travelling on to see the city?
2) Maybe open-jaw back from NCE since we would like to see the Cote-D'Azure?
3) Adding NYC on flight out or back seems to raise the fare dramatically. Any way around this?
4) Would consider chunneling and open-jawing out of London as well if that makes sense

Oh, I've got 80k United miles but don't know how to work that in.

Any help would be appreciated. I don't seem to have the toolset to effectively figure this out.