I wouldn't go so far as redoing the roof - meaning new rafters and support structure, nor sliding the bay window over. Might as well build a second floor if going to that much trouble.

First I would pick a consistent color, either the white of the window or off-white of the gable for all trim. Then I think its a matter of differentiating the bay from the gable end - they kind of blend together with the same siding. So like these examples:

The middle white one the bay blends in vertically like yours, but its the same color. The blue and beige houses differentiate the bays from above them.

So for yours, the eave bracket detailing is rather simple, so you shouldn't do a lot of busyness. Just adding trim to separate the gable, even carrying that as a frieze board across the top. Adding window head trim (maybe as prominent as a crosshead). Adding a water table trim along the bottom (maybe future full watertable of brick or something). I think I would avoid vertical trim on the bay, to accentuate the horizontalness and balance the skinny verticalness of the massing.

I show a window as well, same size as the gable window, if that works in plan. Symmetry forced onto a facade is too contrived, just try for balance.

For the porch, can't tell what's going on in this pic perspective but maybe you could just extend the roofline as a shed, maybe the same slope if it works.