Almost done but questions

Been working on building my 2' x 4' table for a couple years but have a young family.  I want to finally get it done and I may of known my plan at times but with breaks in the build I have forgotten all the details.  Table is built I literally have a small list of items to do but need help.  I plan to have both Torch Height Control and Ohmic Sensing, I have the Hypertherm 45XP with the port on the back that I will be using on this table.  Have a small Hypertherm machine torch that I purchased because I didn't want the long version of the Hypertherm Machine Torch with the added weight.  This table will be using rack and pinion for movement on the X and Y axis and a ball screw for the Z axis that I designed and built.  Have a water pan that I made to cut down on the dust.

Rundown of parts that I have for this
Mesa 7I96 card and Mesa THCAD-10 for the Torch Height Control and THCAD-5 for the Ohmic Sensing
4 of TB6600 drivers from Amazon
3 of Nema 23 Bipolar 1.8deg 2.4Nm(339.87oz.in) 1.8A 57x57x104mm 4 Wires 
1 of Nema 23 CNC Stepper Motor 2.8A 178.4oz.in/1.26Nm CNC Stepping Motor
1 of Meanwell MDR-40-24 to power stepper motors
1 of Meanwell MDR-20-5  to power the 5V on the board and other small power needs

Sensors I have homing on the X and Y's and also have max on those axis's as well
Z axis I have the spring loaded for homing and then I have a max travel as well

Questions I have

1. Will the 2 power supplies be sufficient?
2. THCAD-5 wiring I'm assuming this is wired like the THCAD-*10 for Torch Height except the + is from the tip of the torch and the - is from the water table?
3. Stepper motors will they be strong enough?  I purchased them several years ago and was trying to watch my spend at the time.
4. I have seen others gearing down their stepper motors I think 3:1, I currently wasn't planning on it will this cause me issues?
5. I was planning to run water in the water table but I live in Minnesota so it get's cold and can freeze even in the garage, is there something else that people recommend in the cold climates?

I had started configuring Linux CNC, don't remember where I made it to but I'll probably have questions on that when I get back to that in the next couple of weeks.

I've been using the below diagram that I had found on a different post for my wiring. 
Thanks in advance

Mike

This is the table I just pulled up on the 24V power supply, I'm thinking it's 0-1.7 Amps
 
Thanks for the info on the torch being negative will wire it that way
Gearing I'll try to figure out a way to gear it down with this type of bracket
How much baking soda?  I had never considered antifreeze or alcohol so I will steer clear of them and use the baking soda like you recommended.  Didn't know of fluid because I've seen others purchase a type of fluid before but can't remember what it was.

Looking back I don't think my original post had the electronics picture
 

Or the Z Axis picture


Here's the 36 Volt power supply that I'll have to fit into the electronics box from Amazon
 

I really wish somebody would burn that lowrider circuit diagram, its just plain wrong with its power supplies!
Its good to see you adding a 36 volt power supply!
As a rule of thumb the total power you can take from a power supply for steppers is about 1.4x based on the stepper motor current setting eg. an 11 amp supply will handle 15 amps of motors which is a bit over rated ror 8.2 amps of motors. 7 amp would be OK (eg 9.8 amps max motors) but may not save you much cash or space. The Meanwell 24v 1.7 amp power supply just won't cut it!