Help needed! How to root a cracked screen Z Ultra? topic

Hi,
My Z Ultra's screen is cracked and i would like to use it for my TV as a Andriod-Box replacement, because it's actually still usable i think. Now my Problem isn't finding a suitable Rom(i think), general knowsledge about rooting.
I think i got all the needed tools like a microsoft bluetooth keyboard with touchpad(regular usb mouse and keyboard too if needed), a MHL/USB(all-in-one) OTG adapter, HDMI cable and the universal USB micro to usb adaptercable.

SO my questions are:
1) Can i root without actived USB Debugging? (i can't activate it due to the cracked screen) ...Most important!
2) Is Towelroot still good? Or are there other easy root methods for newbs?
3) anything else i might have forgotten?
4) i think that a Sony Companion free system is usefull for Flashtool or am i wrong?

Thanks for reading any maybe helping :)