For Science!

I would still prefer bending, or sand down the side panel I guess you can give it a try if you're willing to replace it if it all goes wrong

This is probably not feasible, but I shan't shout at you since you asked first They are hollow and rely on being sealed, so if they are punctured, the effectiveness of the cooler will tank. Bending them is "probably" safer than sanding, but it all depends on how badly it touches the side panel.

No, you just leave it be, and try to obtain one more bottle and top it up with the same coolant. Worst case your reservoir may not be filled to the top, but it will not affect performance of the loop. 1 liter should be more than plenty to get the air out of the key components.

I think there is a good chance it is less than 1 liter (dependingon tubing length) but it is definitely less than 2 liters

No, the pre-mixed coolant should be used as is, no dilution should be done. If you list out your loop components, we can have a guesstimate as to how much volume there will be.

No, I wouldn't recommend mixing coolants. Given that the 250 ml of EKWB should be diluted 10x, this would mean you have 2.5 L of EKWB 1x coolant. Is this not going to be enough for your loop?

It aint going to be energy efficient but either the hot side of a peltier or if you could route the exhaust of a water chiller, this might still work.

most pumps are rated to operate below 60 dregrees fluid temerature.

I would use something more powerful, but if you don't want to buy anything extra, it may be worth a try, just make sure you neutralize everything with plenty of water afterwards.

Use a pipe cleaner.

It looks like it has been really scratched up by the particles, at least thats what it looks like to me based on how the acrylic reservoir looks like. I assume you can't wipe off the white-looking things and its actually scratched. In that case I think you can only throw the tubing away and re-bend. With larger acrylic parts you can use polish meguirs for example to restore it. The metals parts You could consider using mayhems blitz part 1 and 2, just be careful with the stuff.

Getting a stable opaque coolant is not so easy. As you don't have soft tubing it also rules out the most common reason for gunking, which is the plasticizer. Assuming you don't have a silver kill coil, I would just put it down to the fact that the EK opaque coolant just isn't super stable. I personally don't recommend opaque coolants generally, but if you must perhaps consider Mayhems as although they do not have great documentation, anecdotally it would appear they are more stable than EK. However if I were you, I would ditch opaque coolants, and go for either clear coolant, or co

Legal to watch, sure, but don't take what YouTube leaves up to be the word of the law, they only recently started taking down COVID-19 misinformation. Whether what they do is legal is gray zone imo. If they did what they did to an "ordinary" citizen, I think you would agree that this would be frowned upon. And even if they were criminals, you still as an ordinary citizen should not be breaking into their PCs. If you toned down the tech a little bit, imagine if an ordinary citizen was tapping phone lines of "potential" drug dealers, and happens to land on a drug deal, and so informs

Gray zone imo, its still vigilante as he does not have legal authority to conduct the searches, and this demonstrates more of the lack of resources of the Indian Cybercrime Police than legitimizing his means. I am sure if he did the same for example to expose malpractice within the Cybercrime Police unit (for example) they would not be thanking him, despite it is the same task and process. And no, you cannot infiltrate another persons computer legally across borders.

If he hacked the scammers with the intent of disclosing to them their security flaws and with the aim of patching it up, then this would be considered white hat hacking. What you present is simply vigilante justice, which in itself is a debatable subject.