I would be inclined to say nay to the bumper on an all fiberglass car such as yours. I presume you have straightened out the irregularity where the front end is seamed together.
But, using your pics to compare with and without the bumper, I think it looks better with the bumper. The shape and position of the banana marker lights makes no sense without the bumper line, for one thing.
Nothing says you have to have an oem CHROME bumper there. I like the idea of a tubular bumper, like a nerf bar. If I had done the bodywork to the front end to make a perfect V, without the irregularities, then that's the look my car would have right now. Instead I got a fiberglass copy of a front bumper from opelspyder and painted it yellow.
Many euro dudes have used the fiberglass bumper as a base to form a perfect V front end and then fiberglassed or puttied over it to blend it in. This is a look I like a lot. It imparts a GT Bumper-shaped bulge to the front end and gives the nose a bit more character than what you have now. Of course, if you blend any kind of bumper concept into your front end, rather than a free standing bumper, you still end up with a fragile front end that you're terrified of bumping into something with.
Try bending an 1 1/2" or 2" piece of pipe into the shape of a GT bumper and maybe paint it black, so that it looks like rubber.
The great thing about your car is that you don't have to stick with any of the oem design aspects, you can do whatever you want that looks best to you. Later, if you don't like it or get bored and want to go in another direction, you can fab up some other new fiberglass creation. Have you thought about making a hatch/trunk lid? You've got the perfect car and skills to install some kind of rear access.
Just food for thought.....