I'm planning to format the system memory in order to restore the demo play count on Bravely Default (If it works for resetting the play count, I read somewhere that it does, but it might have had been fixed with system updates). I found a really cheap Bravely Default game that I'm planning on picking up, however, I want to transfer the stuff from the demo over. This wouldn't be a real issue if I kept the save file before deleting the demo, but I didn't, and I can't play the demo anymore.
So here's a few questions, I'm hoping to get some answers, so that I can judge if it's a smart move to do, or to Skip this and play the game without the demo content.

1) Will backed up save files (Save Data Backup) for Pushmo(Pullblox), Crashmo(Fallblox) and Super Mario bros DX work after the format? Because I don't wanna lose all my progress on the first 2 games (especially not my own puzzles)
2.a) Does the format remove all my friends?
| If yes
2.b) If I write the FCs down somewhere and put them back in after the format will the other friends need to re-enter my FC in their 3ds too?
3.a) Does the format remove all NID data?
| If yes
3.b) Will re-entering my NID data restore my purchases and $ ?
4) Is there any way to preserve Miis? (I thought about transfering them to the Wii and then back after the format, but I got a good deal of Miis)

That's about it for now, I might ask a few more questions based on the answers I get.
(I thought about asking this in 3DS noob paradise, but it seems the thread deals with Flashcart issues, sorry if I'm mistaken)

Thanks in advance for any help you might give.

 

Thanks for answering, I was hoping my fc would stay the same so I don't lose my friends. Seems like replaying the demo for bonus content isn't worth this much trouble.