That is a great looking snake!
The prominent features in any enclosure to me are: Water bowl and hide(s). Everything else is clutter and decoration. Whether or not the cage looks good to us: The real test will be if your ball python likes it and eats consistently.
I know you are doing the 'gradient' thing. Not my favorite method--since the water bowl can either be on the 'hot' or 'cold' side or precariously placed in between...
If your ambient is 90F on one side (imo) that is too hot. 90F should be the belly hot spot created by your heat pad not the air temperature. I personally would not go over 85F for ambient. Smaller ball pythons tend to be much more forgiving of higher temperature imbalances...so no big deal atm. You asked if you need a heat pad? If you use a surface temp gun and the bottom of your 'warm' side is at least 85: I would say no...it would be nice though. I keep ambient in my collection at 80F: so I have heat pads on every one of my ball python enclosures with a hot spot calibrated to 90F. In the summer when the temp. goes up to 85-88 in my snake rooms: I turn off my heating mats.
I see that you are using those plastic gauges to measure temp/humidity in the enclosure...those are wildly inaccurate. I would recommend finding a digital equivalent and as mentioned previously a surface temp gun for contact temperatures.
I didn't see any pictured, but, hopefully you are using locks for the top of the cage.
Last thing, I noticed that you have a Croton (plant) in a pot---these require high light in a terrarium setting: I would take it out. If there are any other live plants in the enclosure I would be wary of them surviving close quarters with a ball python-these snakes are quite strong and can easily overturn them.
Note: I like the sticker.
As for red lights: I know they can see them. I suspect the snake would prefer a ceramic heat emitter with no light output.