Every feature on every plan: logic, uploads, webhooks, team permissions, embeds. Try either plan free for 14 days, no credit card required.
Forms over their monthly submission limit stop accepting new responses until the 1st (or until you upgrade). You'll see usage clearly on your dashboard well before that happens.
No. Archive a form you're done with and its slot frees up immediately. Its submissions stay available forever.
Monthly, through Stripe. Change plans or cancel anytime from the Billing page; changes prorate automatically.