Venue 11 Pro power issues, very disappointing so far

I am testing a Venue 11 pro atom version with additional battery type keyboard, I am finding charging is slow off the new type charger and  4 hour charge is not happening at all.

couple of questions if anyone can help:

why do I not get 4 hour charge even when the unit is shutdown

why does the bios report incorrect PSU when alerts are enabled saying charging is reduced and told to  get a correct PSU, it is the supplied unit and micro usb cable.

why does the unit switch off once the keyboard battery is depleted even though the tablet us 100% what is the point of a the keyboard if you can't use the keyboard from tablet power, and the same even when charger plugged in!

why does it just power off on depletion and not warn of capacity  depletion, I keep losing data.

why when plugged in with keyboard does the PSU not supply enough charge to sustain the battery, it still depletes, power profile is set to balanced.

any help would be great as at present not worth the money to kit my business out with these

thanks