I have my thermal pads enroute from EVGA for my 1080sc. I game at 1080p and keep my fan speed profile decently aggressive. Is it absolutely necessary to wait for the pads before I unbox and install my new card under these circumstances? My "old" 980ti only got to 55c in games like Witcher 3 and The Division, as my case has great airflow.

Per EVGA themselves, the VBIOS update and the thermal pads are optional. Not required.
 
http://www.evga.com/thermalmod/
 
You'll be just fine.

Despite what is going on around the internet, I have yet to have issues with my 1070 SC. I have been playing TW3, SW:BF 2015, and Batman AK on Ultra for 3 weeks and not one problem(yet).
I added thermal pads, updated the vbios, and changed out TIM as a precaution/personal preference. Certain people will continue to complain, but maybe 45-50% of us are fortunate enough not to have overheating/black screen/fan issues.
As arestavo pointed out, optional unless you have been/are experiencing issues, you should be fine.
Flame on losers......Get out that pacifier, thumb, or whatever you need to do in that dark emo closet to stay happy(rofl). Just for the love of <insert chosen deity here> please stop whining....it's getting really old!

Thermal pads are optional. Vbios update is recommended. Since you're already running an aggressive fan curve you can skip the vbios update too.

Awesome. Thanks guys.