Redro

I would bring up to date financial statements.
I am aware people in South Korea usually bring up to date national pension documentation as proof of assets when interviewing at Seoul. You might want to bring the last 3 months of financial statements or maybe May to September to show you've maintained the balance. 
p.s is it possible to share your timeline? What was your priority date? 

Socio-economic isn't a direct driver for immigration VISA issues.  Plenty of VISAs are issued world wide in "poorer" GDP countries.  The biggest driver is the validity of documents,  Nigeria and Pakistan are the two most problematic countries mentioned on VJ as the veracity is hard to check.  Nigeria also has seen lots of issues with VISA "agents" such as telling people to put married on a B2, then that person tries to get a marriage / fiance visa and is denied since they can't prove that they were never married.  Add in overstays and people adjusting after entering on a tourist Visa and you see why Nigeria is so problematic.  All from the Nigeria which has the highest GDP in Africa, well over a 100 billion USD over Egypt.

A good corollary is looking at the passport strength. https://en.wikipedia.org/wiki/Henley_Passport_Index  None of the African Nations are in listed high.

Having to be there physically for the marriage.   Can be a big problem with all the travel restrictions.  If I were to do it again I would  go the CR-1 route.

The very best evidence of a bona fide marriage is evidence of time actually spent together........That is the bottom line.
-I'm out!

Since the beneficiary is not Korean...Korean is not their native language or alphabet.  Enter Not Applicable.

It's clear you live at the same address.  That's all this document is for.  You will be entering the address in English in one or two places, and the beneficiary's name and address in Korean in another.  Carry on.