Threatening violence sure is a sign of maturity. It is also very useful for your monitor. I am sure people will want to assist you now that you have threatened violence...
That said...
You chose poorly for your first lizard beyond a chameleon. Nile monitors are demanding and difficult. There are many other animals that would have been a better choice before working your way up to a nile monitor. I still suggest that you take it back and get a different type of lizard. Nile monitors just do not fit what you seem to want from the lizard. You will very likely be unhappy with a nile monitor because how he acts now is most likely how he will act when he is bigger. That is just how nile monitors are.
No one here is going to be impressed with the value of your animals. The fact is that you have had one dead nile and another that is not likely to do well unless you make some major changes very soon. That is more important than whether you have expensive animals.
Your last nile, Snuggles, was not tame or calm or in any way healthy. It is dead. That means you should probably NOT use its behavior as a sign of doing things correctly. Monitors act "tame" when they are scared, terrified, highly stressed, and sick. Those monitors usually die... just like yours did. Most of us on this forum have seen other people have experiences just like yours; some of us have even had the very same experience. Learn from what happened. Maybe you should try a new approach to keeping a nile monitor.
Whether you like it or not, your current nile is acting like a "normal" "healthy" nile monitor should act. Nile monitors are SUPPOSED to act aggressive, defensive, crap, bite, whip, and struggle. That is how they escape and avoid predators. A monitor that does not do those things in the wild tends to die. Those that never do it in captivity are generally unhealthy. Your current one sounds healthy and it sounds like you are trying very hard to undo that.
At this point, you have been given the necessary advice that you need. It is your decision to act upon it or not.
Best of luck.
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^x^ Bloodbat ^x^
Monitors, monitors everywhere
and all the food they ate.
Monitors, monitors everywhere,
their parents loved to mate.