@Mike - here is my take on it
Magsafe type charger connection - While it is a nice idea, USB-C is perfectly sufficient and most importantly we will have one less wire to always worry about
"Open lid" function in the keyboard - I imagine this is being able to type with keyboard not attached to tablet? If so then leave it to the potential optional keyboard accessory
Adjustable kickback stand for vertical hold - If it possible to have a functional kicktand in both landscape (full range in this mode) and portrait (one or two angles would do) modes it would be really cool.
Dual / Quad high-end Speakers - Go for DUAL front facing, but pick a good set. We don't care for the QUAD or Branded gimmicks
Optional LTE - Only if it is radio that can cover all major LTE bands in North America, Europe and Asia. Otherwise it is more useful to teather the phone
Carrying case / flipcover - PLEASE have that as part of the package! 90%+ of us will have to protect it when carrying it one way or another. It is nice to have a factory option. Maybe make it different leather colors.
Front facing speakers - Yes, DUAL good quality front facing please
Miracast - WIDI is already part of the Intel chips, this would be nice but redundant
GPS - No need. I cannot imagine anyone navigating with a 12" tablet. Every phone has already
Keyboard + Kickstand magnets for tent / folded mode - Why do we need a tent mode when we have a kickstand?
USB-C Powerbank- Yes, please. Better yet, please make the second option below
USB-C charger-powerbank-docking station - YES! It would be super cool and useful for those who have to travel a lot and need productivity on the go
Protective case - How is this different than Carrying case? Either one would be fine
Physical rotation lock button - A software option is already in Windows, no need to re-invent the wheel and spend resources on something that would rarely (if at all) be used
Haptic feedback - Would be nice to have, but not a deal breaker
Ambient light sensor - Pretty much a must have these days! Plus it will help you with power management
Double tap to wake - Once you try that, there is no going back haha! Please add that. I've actually asked MS to add that to SP4 last year
LPDDR4 if possible - It is marginally faster, but saves a bit of power. Go for it if you can get it!
Alert Slider as in OP2 - It would be nice to have, but not a deal breaker
Volume Slider instead of buttons - That would be sleek, but again not a deal breaker
Trusted Platform Module support - ADD THAT PLEASE. Then IT departments can buy them for work
Push-to-Snip in Wacom Pen - Don't care for that. But please have and "erraser" on top
Physical Windows Button - ONLY if it is on the side and part of something like power botton. It is not Win8 era anymore and there is no need for it. Just look as SP4
Notification LED (charging and other) - Not required, but if you add it plese do NOT make them blinding bright
Fast charging - With big battery we pretty much have to have some form of fast or faster charging
Custom "Eve" lighting - Go for it, it will make for great marketing in coffee shops! We'll brag about it and spread the word!
Volume wheel with customizable functions - Leave it out, you will need software for it on top of Win10 and that will lead to potential bugs