I'm a little confused on the bumper rules, hoping someone can help me.

17.1.7 No part of the bumper system may be removed or modified except for the rubber bumper moldings.
17.1.5 Turn signals and marker lights maybe removed. Exposed holes in the body work from these lights may be left open or filled in.

Can I fill in the holes in the bumper after the rubber is removed?
Can I weld in a cover over the holes where the turn signals would be, to create a smooth bumper?

Yes. We just don't want significant alterations to the structure of bumper.

If you're driving a 924S, you might want to use those bumper openings for brake ducting since we don't have fog light openings. Welding to the thick aluminum bumper with sheet aluminum? Sounds troublesome...
Those amber light housings don't weigh any more than a popcorn fart. You could bolt them back in at no cost and be done with it?
....then you could use them to let your opponents know you're passing them on the left or right. Might be polite to use them to let people know you're pitting during a night enduro?

My 924s is built to SP2/944 Cup rules. I registered for this website when I was building it. It was originally built for Spec and I still have alot of the parts that I swapped out for Cup. I have a stripped 944 sitting here so I decided to build a Spec car. That and the cost to run at the front of Cup is getting out of hand.

As far as the bumper goes, I don't like the looks of the lights on the bumper and that is my only motivation to do this. My family owns a manufacturing plant and we weld aluminum on a regular basis so it costs me nothing to weld it up. I also do all my own work including paint so I won't be paying anyone for that either.

The only lights I plan on my competitors seeing are my tail lights anyway jk

Sounds good!

Bill Comat was telling me about some of the motor builds in Cup - they are worth more than my car!

Yeah, Bill's the leader with that.