The dresser in Allie's room or a booth in any Pokémon Center to the right of the main counter.
You can't, but Windows has a built-in Magnifier app.
You should be able to find a couple of walkthroughs in this thread with the Search function. For anything else, you're going to have to be more specific with your questions to get meaningful help or advice.
There's no gallery mode, so you miss a lot of the point with an advanced save. You can skip a lot of grinding with debug.bat to add Pokémon, set their levels/moves and give yourself items, though.
Hinoarashi plans on making a male Trainer story once the current is finished. It would be a new story in the other half of the Region, but both will be able to visit each other's. It's a long way off, though, obviously.
If you can't use Fly, try opening the game with debug.bat and changing Switch 112 (NO FLYING) to OFF.