Disclaimer: personal opinion ahead
The white vertex car you posted is on rolled metal arches and looks fine. The wheels fit nicely, even with the wide skirts. You'd get the same effect by spacing your existing wheels, or acquiring some wider wheels. By fitting fibreglass wings with wheels that don't fully fill them, the car won't look any wider. The opposite in fact; the increased space between your tyre and the arch will make it look higher/narrower by creating the illusion of a reduced track-width.
Regarding the front bumper comment, I made this image for Mark Moon's car, but it stands for any car with aftermarket bodywork paired with the stock front bumper.
The black lip creates the illusion of reverse rake/a raised front end, which just looks odd. Ideally the black touring lip would be an extension to the front, lowering the bumper below the skirt line, rather than meeting the skirt line.
As you say, painting the lip is a possible workaround, but IMO this doesn't look right (as seen below):
The Vertex bumper you posted is nice and would definitely work.
It goes without saying that all of the above is subjective; it's simply what I'd do if I was in your shoes