7 days is already significantly limiting, the "nagging paywall" would drive me away from the app entirely. The extra free time from adding card info isn't terrible. I imagine you'd need to play with the numbers, e.g., is 7 days even enough time to evaluate the added complexity over a traditional to-do app? Maybe it could be 14.
I greatly dislike case-insensitivity. It's a source of many problems for users and implementors.
For implementors case-insensitivity means the need for full Unicode support is urgent, while Unicode canonical equivalence does not often make the need for full Unicode support urgent. In practice one often sees case-insensitivity for ASCII, and later when full Unicode support is added you either have to have a backwards compatibility break or new functions/operators/whatever to support Unicode case insensitivity.
For users case-insensitivity can be surprising.
For code reviewers having to constantly be on the lookup for accidental symbol aliasing via case insensitivity is a real pain.
PowerShell is case-insensitive, you don't need to type caps for variable/function references if you don't want to. You'll still have hyphens, but in an interactive shell (as opposed to a script) there are many aliases you could use that avoid hyphens (or you can make your own).
I know everyone has their own workflow, but I'm still surprised anyone actually goes to Google's home page anymore what with their search bar being accessible from practically anywhere (browser address bar for example).
I don't remember the last time I actually went to the Google home page. What leads you there these days?