Okaaay I got the time to put the coolant in the system and burp all of the air out, took about an hour because I had to make a trip to get more concentrate coolant when it became clear the new 3 row radiator holds A LOT of coolant. I let the Jeep idle for 30-40 minutes with the heater cranking and the radiator cap off until the air became red hot and the temp gauge stayed in the same spot no matter what. Never even budges from just under the center point now so the actual overheating part is solved! Whoohooo! Cooling fan never once came on still (but it never went past half way so I don't expect it to). So for now I will continue to monitor the temp closely but I think it's good now. Found a place that will "rebuild" the computer for $100 so maybe if I get really uppity one day I'll send it in and have it re-chipped but not for now. The water pump was most likely bad as well so its a good thing I changed it, I say that because the howling noise that used to come from that area of the motor is completely gone.

Causes of overheating: Bad thermostat (died stuck open) and also a sub-standard/dying water pump

Where my temp sits now no matter how long I let it idle. So thank you all for the advice it was greatly appreciated!

Small edit: took it for an hour long drive and the cooling system works great, never overheated once and sits in the exact center 50% of the time with the rest of the time being just below center. My GEN light came on just down the block so I stopped to look and found heinously corroded battery terminals. Drove back home and poured baking soda/vinegar on them then scrubbed them clean. Also added distilled water to the battery since when I inspected it there was almost no water in it. Drove another 25 miles and no GEN light and the temp stayed perfect