Questions about 3DS System Transfer (about the source)

[-Apples-]

I got a new 3DS today, and I realized that I can't use the same Nintendo Network ID on both systems, so I decided to go with the system transfer from my old 3DS, but this one sentence stopped me from going any further. It said something about the source data being formatted. So I have a few question about the source 3DS. I already know about the target 3DS after reading more from the internet, but they didn't say anything about the source.

1. Do my funds on the source 3DS get wiped since I can use them on the target 3DS?
2. Does update data for ACNL and Pokemon Sun and Moon get deleted as well? I know the game data doesn't since it's linked to the game copies and not the memory.
3. Will my source 3DS have all of the photos and sound recordings I made (if stored to the SD)?
4. What else will happen to the source 3DS after data transfer?

 

[KeatAlex]

I don't know 1, but 2 yes. The update data is deleted and you'll have to update all your games again. However it works just the same after you do. 3. yes, at least mine did. 4. After i transferred everything I found that my VC game data had been deleted so I have to restart oracle of ages :'[ also my themes were acting funky but that was a simple fix. I recently transferred 2 days ago so if anything else is different I haven't encountered it.

 

[-Apples-]

I have one last question. If I transfer data to the target system, then put in my ACNL cartridge (the one with StarFall) on the source system, does that corrupt my save data for ACNL on the physical copy?

EDIT: I just saw what happened if you do data transfer between two 3DSs and put in a physical cartridge of Animal Crossing after formatting. It does not ruin the town. It only does do on digital copies. I don't even have a digital copy of ACNL, so StarFall lives, for now.