Even with doc. 8168 procedures, if you have the required visual segment at minima, whether DA or MDA (not applicable for some Cat 111) the continued descent to the runway is still part of the approach, it is the visual segment of the instrument approach procedure. This just a strue for a straight in as a visual circling as a segment of an instrument approach.
I agree that it's the visual segment of the approach, but the visual segment could also start well before the DA or MDA, once the aircraft has visual reference to some part of the runway environment. At some point there needs to be a landing phase!
As far as ATC is concerned, "cleared for approach" means your clearance limit is the threshold, until you get a landing clearance.
I don't think so. When you're cleared for an approach, your clearance limit is the missed approach holding point. Obviously if you receive landing clearance, you're allowed to land if you have the runway visual - obeying all the rules associated.
An instrument approach is only terminated at the DA/MDA if you commence a missed approach.
I don't think so. The instrument approach procedure is terminated at the missed approach holding point, which is the clearance limit. The missed approach point is where you transition from the final approach segment to the missed approach segment - both part of the instrument approach procedure.