Can thermistor wires be connected to ground?

I'm designing a printer and it's not clear to me which connections can be attached to general GND or general 24V. This seems poorly documented, so I'm looking to find out if there are any conventions or experiences.

The printer is going to have a single umbilical running to the control box and I want to minimize the number of wires, so I don't want to run for example 4 ground wires through my umbilical if I could connect them all together and run 1 ground wire. But it's hard for me to find information about how the electrics are implemented. I'll be using a BTT SKR 1.4 turbo board and Marlin firmware.

I know about electronics and microcontrollers so I know there's multiple ways to setup the pull-up resistors both in hardware on the board, and in firmware by setting the pullups internal to the microcontroller. For things like a part cooling fan, the fan connection on the board will have two wires, labeled - and +. I assume there are two possibilities, either the + is just a straight 24V wire and the ground is connected to ground via PWM, or conversely the - wire is connected to ground and the + wire is connected to 24V via PWM. Either way, I should only have to run 1 wire than run 2 wires.

The 24V heat bed has 2 wires for the heater, but can one of these be connected to ground at the printer, or alternately, can one of them by attached to a general 24V at the printer? How can I find this out with a multimeter etc?

Same with the hotend...can one of the heater wires either be connected to ground or 24V, so I only have to run a single PWM wire back to the control board?

What about thermistors...do I need to run both wires for both thermistors (4 wires total), or is there a way only run 1 wire from each?

Here is some research I have done so far, by looking at the SKR 1.4 board. It seems impossible to find actual electrical drawings of this board, but we can make some inferences from the board schematic.

Based on this particular board, image here : [teamgloomy.github.io] :

The thermister connectors have two pins which are labeled as "0.23" and "AGND". I assume the 0.23 is a microcontroller pin number, and AGND is "analog ground"; I think that's usually designed to be isolated from other grounds, but nominally at the same voltage as the standard ground. I don't know if there would be any advantage of running a dedicated ground wire for the thermistors, considering said "analog ground" wire would be bundled with the stepper wires and heater PWM wires anyway, thus doesn't seem any better than a shared ground wire. Thoughts on this?

The endstop connectors are labeled +5V, GND, and a pin number. I think I could use shared 5V and shared GND at the printer, and only run 1 wire through the umbilical. Any thoughts on this?

The heatbed and hot-end connectors are two wires, labeled with a pin number and "12V/24V". I think I could connect this to shared 24V, and only run a single wire (the "pin number" wire) through the umbilical. Of course, the single wire plus the shared 24V wire must be able to handle the 7A of current. This seems low risk.

FAN1 is simply two pins with 24V and GND, so no point in running this from the control box at all. I guess this is the hotend fan, so it's on whenever the printer is powered.

FAN0 is two pins labeled with 24V and a pin number, so I could just run the one wire for FAN0. I guess this is the partcooling fan...I don't see any other PWM fan connections.

The TFT display connector is 5 pins: RST, RX, TX, and "NPWR". No idea what NPWR is. If NPWR is 5V or 24V, I only need 3 wires for the TFT display.

Given the above assumptions hold, I think I could run the whole printer with a single DB-25 cable:

Pin function
1 Z A1
2 Z A2
3 Z B1
4 Z B2
5 X A1
6 X A2
7 X B1
8 X B2
9 Y A1
10 Y A2
11 Y B1
12 Y B2
13 24V shared supply
14 24V shared supply No. 2 (for current capacity)
15 Z endstop signal
16 Part cooling fans (24V pwm)
17 Hotend thermistor “minus”
18 Bed thermistor “minus”
19 Bed Heater “minus” 1
20 Bed heater “minus” 2 (for current capacity)
21 Hotend “minus” connection
22 TFT RX
23 TFT TX
24 TFT RST
25 Shared 5V supply, or reserved if I put a 5V regulator on the printer
GND

Of course this means my printer can never have a bed probe, fancy LED or whatever, but the idea of using a single DB-25 connector is really attractive.

Where are E0 stepper pins?

You mean I need an extruder to make a 3D printer?

Yes I guess DB25 is right out, but the point of minimizing wires is still valid.