Minutes, around the clock. The first touch is acknowledgment and routing, not a sales pitch. Your people still make the human contact; they just make it while the lead is still warm.
No. The first reply is short, plain, and written with you in your voice. Its job is to say a real person is on it, offer the next step, and mean it.
Yes. Missed calls can trigger the same flow: an immediate text back, the inquiry logged, the callback assigned. A missed call that gets a text in one minute usually stays your lead.
It depends on scope, and I will tell you before anything is built. The thirty-minute audit is free, and if the fix is not worth building I will say that plainly.