I can tell you guys the way I did it bcoz I had almost same situation like you guys
I met my wife in person at her home for the first time so i fill up her home address for the place we met first in person
and for the question when and where you met - I gave the answer 'Skype video call' and its date.
I dont even have any photo together before marriage other than call and chat details.
I still submit all details of that though i missed some of call details.
I would say what ever documents you can give to prove your relationship that would be helpful to convince the officer.
the marriage photos u need to produce important events of marriage. like ring exchange, number of attendees, reception.
My friend who got married an year back only provided 15 photos of his marriage as it was an inter cast marriage happened in a panchayath registar office not with any relatives but few friends. His wife got PR recently even with out any questions asked, but I dont know how ........ Overall I would say provide evidences as much as you can and pray well.... If the almighty joined our dearest one to us,then he will definitely support us to live a life together.....................................