Try it with no card and pick your plan once Jacko has saved you more than it costs. Cancel whenever, in one message.
Yes. Upgrade or downgrade in one message and it applies right away.
Both. Annual is the most chosen because it works out considerably cheaper than paying month to month, and you can switch whenever you want.
You keep access until the end of the paid period, then the account is paused. Nothing is deleted: your transactions, budgets and conversations stay and come back the moment you pick a plan.
No. The 3-day trial doesn't ask for a card. When it ends, you pick Lite or Premium to keep going.