Codes C0450, C0561, C0040, no Traction Control and ABS light on?

Okay, the codes you have point at a fault in the circuitry for the ABS system. The C0561 is basically saying the there is a fault, and the ABS is disabled and codes are stored. The C0040-00 and C0040-05 codes both say there is a fault in the circuitry in the right from wheel speed sensor. The C0450 code is related to the power steering assist controller. It gets data from the ABS module so that code may be a side effect of the ABS being disabled. The circuit code points more to a bad connection in the harness than a bad sensor. Does your OBD tool allow you to look at live data from the wheel speed sensors? If yes, then you could watch that and see if there is no data or if the data drops out while turning or if you flex the harness. GM had issues with the right side harness on many vehicles around that time period so it's possible you are a victim of that. If your scan tool doesn't show you live data then you might want to upgrade to something better like one of the Autel Maxisys or Launch tools like the CRP 910 or Millennium models. Topdon Artidiag tools are also really good. All of them have various levels of abilities and control and cover multiple makes and models.
Now if you see that the right front signal is gone you will need to test the circuit Fortunately GM made this a bit easier as those are active sensors. There is a reference voltage feed to the sensor and the sensor acts like a switch turning the signal on and off as the magnetic ring passes the hall effect in the sensor. If you unplug the sensor one wire should have 12 volts on it with the key on. If you have that then suspect the other wire is broken going to the ABS module. Repair that and then erase the codes. Take it for a drive and see if any of the codes return.

Okay, the flashing light was due to the P0300 which is a random misfire of multiple cylinders code. Not the code causing the ABS issue but not a good code. Any of the models I listed would cover all those makes with full testing of all modules and bi-directional control of most of the systems. It comes down to what you want to be able to do. The higher-level tools simply add more functions and a bigger screen. Something like this tool has far more ability than most people will use, but it does a lot as well.

https://www.aeswave.com/Autel-MaxiSYS-MS906s-with-2-yrs-Updates-and-Warranty-p10509.html.

The Topdons are a good tool. Most aftermarket tools actually do more than many of the OE tools.

With the tool you should get a much better view into what the car is seeing and the ability to see live data of pretty much every item on the car is a great thing when it comes to diagnostics. As for service info, I don't know of any good free sources online. You can get access to mitchell and alldata for single vehicles and you can go directly to GM as well but be prepared to spend real money there. One thing with most of them is that you can print most of them off for later use, if you print them out as pdf files and save them on a drive that's your choice. You can buy the actual GM hard copy from Helm but that manual set is $300.00 You might want an account at https://www.corvetteforum.com/ as well. We use Alldata on this site but I use all of them in the shop.

Okay, the right front lack of signal is why the traction control is off. That shows as the zero speed from it. There is a broken wire in that circuit or the EBCM has an issue. What I suggest would be to jump the left front sensor to the right front input. If you now have a speed, there then it's in the harness. If there is still no speed signal, then the EBCM is the problem. You could test for continuity the same way. For the first test you go to the ECBM on the frame rail and the connector on it. Find pins 6 and 18. Now find pins 21 and 34. Use a couple wire jumpers and connect pin 6 to pin 34 and pin 18 to pin 21. Take a short drive, got a speed signal now? Yes = it's a broken wire in the RF harness. Then it's just a matter of tracing which wire, for that you can use a meter on pin 6 (tan wire) and at the sensor end one of the two pins should have a good connection. If you find that wire is good, then the other wire is the problem.

From the scan data I would say the harness itself has a failure in the right front wheel speed sensor input. The hub and sensor should be good, but the signal isn't getting to the ABS module or there is a failure in the module itself. The jumper test I mentioned would pinpoint the issue as the harness or the module. If jumping the left side to the right at the module shows the same signal on both graphs, then it's a break in the harness. If the data for the right side still reads zero, then it's the ABS module.
As for the P0300 code Use the live data on that tool that shows the individual misfire counters for the engine. However, we like to keep each item as a different question to make future searching easier. As such I would ask that you start a different question about the P0300 code. Include the data that the scan tool shows. If it is true random multiple misfires a vacuum leak is a common reason, as is low fuel pressure.

In this image you posted it showed no right front speed while the others are showing varying speeds. That is why I suggested the test. However, if you have already done the signal testing of subbing the left front to the right front at the harness connection for the right front and had the speed showed up then the harness is okay. If however, it still doesn't show with the right front hub connected, the hub itself or the speed sensor in it is defective and it isn't sending a signal out. Wouldn't be the first new defective OOB part I've seen lately. It should be covered under warranty as the sensor isn't a replaceable part on it's own. If you have access to an oscilloscope, you could test it directly, simply connect the sensor to the scope and spin the tire, you should see a clean signal out put.

You could also swap the right feed into the left, if you get nothing then the hub signal is missing.

Voltage drops could cause codes for sure. However here is what your codes are:

C0450-5A - Variable steering assist actuator implausible
C0561-71 - ABS Disabled due to unknown fault - Data Stored
P0300-00 - Random multiple misfire
B1420 - Low device voltage, Door module in each door
U2100-00 - CAN network data issue

From the looks of the scan data, I would say you have an issue with a door module or one of the locks sticking. The drops could be a door lock trying to lock or unlock. Connect the tool up and try the locks and windows on both doors, do any of them cause the same voltage drop?

The ABS and TC are interconnected and the Variable assist actuator implausible is commonly a sign of a bad connector at the actuator under the car by the steering rack.

Over 4 amps is a serious draw! That is a motor stuck on or similar if it was something like a radio or BCM that sort of amperage would be causing magic smoke release. A fast way to locate that much draw would be to do a millivolt test on the tops of the fuses. Take your meter and set it for the lowest volt setting. Now probe the fuses on top and see where you have voltage. A vehicle that is asleep will have a barely measurable or less on the memory and BCM. Charles has the method I'm referring to - https://www.youtube.com/watch?v=lRcj1fQcWwU I usually try it first when it's a large draw (or I grab the thermal imager) That much flow usually shows up. I suspect it will be that the motor isn't triggering the module properly and it's acting like you are trying to put the window up, even if you are not touching the switch.