OK, so I am almost ready to start this up. First I have a few questions.
1. I have previously used cIOS downgrader to change the IOS of 3.4. Wii this guide still work?
What you used is actually IOS Downgrader, not cIOS Downgrader
2. I have previously used Install Shop app (same in this tutorial) so will I need to run it again?
No
3. I have already installed IOS16-64-v257-prod.wad and cios_fix.wad. Do I need to install them again?
No
4. I have Animal Crossing, so what do I do to make it playable?
Install IOS 38