Cleaning fees - why & when to charge?

Yes, a guest expects a clean place. I’m upfront that it costs me xxx dollars to provide this. As i don’t provide daily cleaning, it is the same charge for 1 night or 15 nights. Under your system I would need different nightly rates for every different stay length. Would be impossible.

Yes, if practical, such as long-term rentals, it is completely common to pass on cost of electricity, wifi, etc to tenant. That way they control costs and usage.