The tool is awesome, I tried it for a few hours and got the deal right away, even though the UX issues are in plain sight - still worth it. You should read the story about the team also, it's inspiring!

Now, to the issues - there's one super annoying which I'm hopeful the team will fix. Goals have a progression, and it has sub-goals. It would be expected that completing the subgoals complete the parent goal (each progress is manual, apparently). I can see how the approach you have can be useful in some cases. Yet - adding a checkbox "Subtask completes parent goal" or something - would be greatly valuable - and expected.

The other issue is that "weekly habits" are not weekly, they still expect day when it is done. A weekly habit = done any time within the week. It doesn't need a completion day, but a completion week. A monthly habit too - it should be finished "once within the month" not on specific date. Check out how other habit trackers work.