There is some confusion of the issue at least in regards to my statements
I don't use the pc as a phone charger
But when I connect my cellphone to pc to transfer pictures, or videos, or to cable tether for internet, the phone automatically draws power to charge the battery, so it is using the USB port, and there is no way of stopping that
And your phone will do the same thing if and when you transfer pictures etc..
If there are other devices like a memory stick or portable USB drive on that port using shared adapter, then THAT power has to be shared among all of them and it's Not enough power
Same thing happens when I plug in the wife's tablet to transfer her country music video files and shows from the laptop to the tablet
An adapter port is a great place for items that have their own power , printer scanner etc..and are not all used at the same time
Consequently I see no problem with printer mouse and keyboard on a shared data self powered port adapter
Think about it, if your using the mouse you aren't typing on the keyboard, and if you are typing you are not scrolling the mouse or printing
Mouse and keyboard are low intensity items, lots of CPU cycles happen between key strokes even if you are a speed typist
I use individual USB ports for my various external hard drives and video capture connections, my printer spends 95 percent of its time unplugged turned off
Data transfer to external drives, USB sticks, and scanner input, is the heavy traffic that needs open data lines, and fill USB port power
Mouse and keyboard, are like comparing a smart car, to high speed commuter rail traffic