1. You will need to collect iTunes recordings from the iTunes folders on your computer. For recordings that you've added directly to Set List Maker, or documents, you can get them all from the Set List Maker data folder on one of your devices. This video walks you through the options:
https://www.youtube.com/watch?v=1qexwLOosrM2. Yes, your layouts will be included when you export your Set List Maker databases.
3. Devices only have to be online to sync new changes. Everything is saved locally for offline access.
4. Yes and yes.
5. BandHelper uses "projects," which are similar to Set List Maker databases but more flexible because you can share items across multiple projects. More info is here:
https://www.bandhelper.com/tutorials/projects.html. You can import each Set List Maker database into a separate BandHelper project. However, if you have the same song in multiple Set List Maker databases, you will then have separate copies of that song in each BandHelper project. That's not a problem, and is preferred if you are playing different versions of the song, but if the two copies are the same and you want to share a single copy instead, you can use the Find Duplicates button on the Repertoire > Songs page after doing all your importing.
6. I don't see a question here.
7. You could export Set List Maker settings from the import/export button in the top toolbar, and import them into BandHelper from the import button at the top of the Settings menu. Note that Set List Maker has separate settings for each database, while BandHelper shares settings across projects, so you will only need to do this once, from one Set List Maker database.
8. Importing everything but documents and recordings is easy. Importing documents and recordings will be some degree harder depending on how comfortable you are with things like finding files, putting them into folders and zipping them. You can also expect some cleanup after importing depending on how clean your Set List Maker databases are and how much duplicate info you have across your multiple databases.
9. Yes, but if you continue making edits in Set List Maker after exporting to BandHelper, you will need to repeat those same edits in BandHelper until your transition is complete.