Why not GE73? Pretty much the same
GL504GM also good but cannot handle the heat of 1070

To answers your question
1. Yes the power will stop charging when it reached 90% threshold , i think for all modem computer nowdays  not only MSI
2. Basically if you put the fan in auto mode the computer will sense the temperature itself to turn the cooler booster on or off, you can do the
    adjustment in the dragon centre , there is a manual bypass physical button to spool up the fan to 5k rpm on the chassis , once you turn on it will
    run forever unless you turn off
3. So far there is no bleed issue for the RGB steel series Keyboard
4. there is almost no screen bleed , unless the old GT with G sync panel

For me i will go for GE63 or 73 instead of GE75 cause the GE75 price is higher , off cause you got think bezel and killer extend network , the rest is the same thing with GE63 or 73 , and offcourse the GE 75 no more steel series  RGB light strip on part A (if you really like BLING BLING , go for GE63 or 73) Of cause the the GE 63 or 73 you need to take care the hinge as well