1.Loads can only be applied at connection points so if you want to apply a load to an arbitrary point along a line then you must add a dummy Connection component to the line at the required distance to the point. Note that Connection component itself will not be included in the model provided you do not attach a secondary line to it; meaning that only the load will be present at the point by default.
2.The various DOF inputs on the Load component follow the same convention as boundary conditions in the Model component. DOFs 1 to 3 represent translation or force loads whereas DOFs 4 to 6 represent rotational or moment loads.