Is this possibly the start of powdery mildew, or just water spotting? Also baby leaf damage.

I have this gorgeous Escargot, had it for going on 2 ish months. Had a horrendous fungus gnat issue so I repotted into a coco coir well draining mix (left roots alone though). Seems to have helped, as I haven't seen any since. I tried to be careful not to get water on the leaves but unfortunately some did in the process. My questions are,

1. Is this powdery mildew, some water spotting, or potentially both?

2. She started exploding in growth once I got her sitting in a really bright corner, but a bunch of the baby leaves are looking deformed/damaged. I pruned off some of the older leaves to give her some space and to attempt some propagation just in case (pre repotting). There is no white spotting or anything at all on those. Not sure why some are lookin' sad. This is my first rex begonia so I'm still learning. Could it just be damage from the fungus gnats?

Humidity in the room is on average around 40%, temps usually around mid/upper 70's. I have a ball python enclosure in the room so I keep it warmer and more humid in the room anyway. Thinking of adding a rotating fan to help air circulation. I just want her to be healthy, especially since I have 3 new baby rex begonias I just got from the nursery in quarantine.

Thanks in advance for any advice/tips <3