How Badly Does Sunroof Impact Body Rigidity?

Just had my first day at the track with my GT40 engine build. Couldn't get out of the 14 second range due to bad 60 ft :/ Always either wheel hopping or spinning the tires through first. I'm looking into sub frame connectors and boxed lower control arms (avoiding slicks). Now I'm wondering, I know already that the hatchback cars aren't as ideal as the notch's because the body is less stiff/heavier. But what impact does having a big hole in the roof have? Do non-sun roof cars have any bracing there or is it just thin steel? I've noticed that my car is small dents right above the B pillar behind the sunroof and I wonder if this is from body flex. It also appears to bulge out to the side slightly but barely noticeable. Please see the pictures below of the roof in the reflection of some straight door frames for reference and tell me what you think.

Thanks for the good tips. Glad to hear about the sunroof being negligible. Unfortunately the glass is still really heavy. I took it out and they yelled at me to "close my sunroof" when I was staging and I had to explain I left it back in the parking lot XD

The car already has 4 new shocks in rear, but has stock arms. I am purchasing boxed lower control arms and sub frame connectors before I go to the track again. Trying to decide between mid length or full length (obviously full length is better but I am always trying to be budget minded with this car and not just throwing money to over build it for the next owner).