Rubber plants (Ficus elastica) can be hard pruned and can respond well. In the wild they are trees, so they can certainly get bigger if you want. Just bear in mind that that pot is not very big for the size of plant, so pruning may buy you time before you need to repot.
Cuts 1 and 2 look about right - it will look better if you can just above a branch and certainly always cut just above a node. Cut lengths of stem above a node will die back to a node. Cut 3 doesn't look to be a particularly sensitive choice - personally, I would go a little higher and cut just above the branch that is growing up away from the marked position.
Up to you what you do with the prunings! There is certainly material you can use to propagate it. You need a length of stem around 100mm long. Remove the lower leaves, leaving just the growing point and one expanded leaf - they don't need to photosynthesis much at this stage and will dry out if there is too much leaf area. Insert into a free draining medium - potting compost with added grit would be good. Try to ensure that at least one node is below the surface of your compost as this is where the roots will form. Do not overwater, as they will rot easily, and until they root, won't be taking up very much water. Experiment with different types of material - green or brown stems. The first time I propagate a plant, I try a range of materials to see what works for me. Ficus species root very easily, so you should get some new plants.