seems like some of these things could be fairly easily done in instrument fx. parallel compression, for instance, is a breeze to set up in instrument fx, but an annoyance in track fx. Simple parallel compression via instrument effect chains
i like the idea of adding vsti in instrument fx, tho. hardly use plugins, but could certainly be useful to layer xrni/vsti
your last example also seems like a good case for use of instrument fx. just use multiple chains and sends/sums as needed. it’ll keep your mixer sends much more organized and simple 