That's sort of like having backdoor access to your internal network (similar to teredo). Others may use it to gain access to that network. If it's your home, that may be OK to you, but if it is an employer, you may want to obtain approval to do that and be sure all of your hidden services use keys or strong passwords for access.
Nice to see that he linked to rust as a safe alternative to the C's (C, C++, Objective-C). There is a place for Go and Java as well above the system level. Both perform well and are safe.
I find writing to be like this. Write something, go away for awhile and do other things. Come back and refine what you wrote. Once you do that several times, you'll have something worth reading. But it takes time.
I didn't mean to imply that. Sorry. If you can get accepted and if you can complete the work, then it's a good program for you. But, yes, it is very difficult (as it should be).
Spend $9,000 US dollars to get a MS in CS, Data Science or Cyber Security from Georgia Tech. It's a solid top 10 CS program. It will take a few years, but it is definitely a great investment.
If you don't already have an undergrad degree and/or want a quicker program, look at some of the reputable code/security academies that partner with major state universities. They cost a bit more 15K to 20K but are shorter (typically a year or less).
Finally, there are certificate programs (offered by professional training companies) in security, coding, project management, etc. that cost 5K to 10K and last from a week to a month.
If nation states and/or cyber criminals do control most of tor, then you are opening your internal network to those groups.