A closed source app like that seems like the worst choice for an "archive". Better to use a format that you can easily backup and that will still be readable in many years like a simple text file.
Not really if you can code. Even apple notes is not that bad because the database is readable (and there are already script to export). What I fear is when companies lock you data on their servers and you have to keep paying or be a good citizen to access it.
The nice thing about plain text, easy to find archives is that they can even be useful (maybe not for yourself any more) if you for some reason can't use your computer any more.