First off, I am really enjoying the game (more so after the challenge update!)
My ideas are as follows:
Decrease the gravity hammer swing time a bit.
Make automatic weapons not be able to de-scope other weapons. I say this because sniper feels like it’s been pushed into very long range territory by other weapons having the ability to de-scope it so easily. Maybe that was the intention, but it’s a bit frustrating to use de-scopeable weapons at closer ranges. Idk, I’m not a fan of de-scope, but I see the balance in it.
Add a warthog radio!
Combine the armor cores. I don’t feel that fact that so many armor customization items are separated is a good thing for customization.
Nerf the assault rifle a little bit. It does feel a bit too strong.
Somewhat more generous match xp. I am happy with the challenge changes, but I think an average of 5-ish matches would be fair for a level up in the battle pass, at the moment, it’s 20 matches on the practice makes perfection challenge alone.
I think free players need to have a little more armor customization options.
Maaaaaybe someday add the halo reach operator helmet. It was my favorite helmet, I understand if it can’t be added for a long time, just possibly consider it for the future. 
Other then that, I don’t think I have much that I think should be changed or added, I feel like I did, but I don’t remember. Halo Infinite feels great! And we appreciate all the hard work that went into developing halo, and that you are listening to player feedback! Thanks for reading.