Better ventiation should be a priority. If you are getting mold and mildew, there is too much residual moisture remaining in the shower too long after use. Mold doesn't grow on dry surfaces. It's that simple. That means a better fan and the use of a squeegee are needed.

As far as the soap scum buildup, you need to change bathing products to a liquid soap and when you do wash and condition your hair, the shower needs to be well rinsed and possiby cleaned immediately afterwards when you use the products. As well as explore products that have less buildup in the first place.

I used to have a large white marble shower with a bench
seat for 2 people and some glass. I would wash my big dog,
Let him shake, then I would take a shower. I really didn't have
Any problems keeping it clean. I used Scrubbing bubbles
cleaner. About once a month or two I would polish the sides
and surfaces EXCEPT the floor.I used regular marble polish.
It would get too slippery on the floor. On the glass while it was
wet with windex I would use a razor blade. DO Not do this dry!
It will scratch the glass. Also dont polish any surface you hold
on to such as bathtub bottom or edges where you grab
or walk. Sorry about my formatting I am on a cell.

Thank you both, for your input. Our shower is a walk in (no door) and I thought the fan we installed was a good one, but I will admit that I like to take long hot showers. I'm okay with the rinsing and drying and will just start doing that.
As far as the polishing goes, I never considered a marble polish. All of the marble is honed. The shower floor is small honeycomb (hex) tiles so it's not going to get super slippery. Should I pursue the polishing?

I am looking for input here. I wipe the crema marfil shower and open the window, but still get some grout mold and this is after I had shower regrouted and sealed. Cleaning people recommend bleach and Bona.
They use Bona also on the floors, also crema marfil. So yesterday they were washing the windows with hot water and some drops of liquid soap. After they were gone I noticed many large water spots across the floor. I called the service owner and he said the water melted the surface the Bona builds up. To fix this I was to get some 0000 steel wool, lightly sand the spots and then drip in the Bona to cover the spot holes.
OK. So does anyone know if this makes sense or should I hire a stone person to come in and resurface the shower and vanity?
And if Bona is not recommended, what is?