> C++ primer (5th edition) by Stanley, Lippman, etc
is a great book, supplement it with the official one by Bjarne Stroustrup.
> https://www.cse.iitb.ac.in/~cs101/2014.2/lecture-slides.html (c++ course) and https://www.coursera.org/learn/competitive-programming-core-skills (course)
Not required.
> https://docs.google.com/spreadsheets/d/1iJZWP2nS_OB3kCTjq8L6TrJJ4o-5lhxDOyTaocSYc-k/htmlview#gid=1833943059 (problems sheet)
Looks useful, I haven't gone through it but I think it'll be useful once you're in the flow.
> Think Like a Programmer (book)
Has basic questions, it's not bad but if you already are familiar with competitive coding, IHMO it's not worth your time. If you can solve Codeforces Div2 A, B, C, D or Div1 A, B level of questions skip this book.
> Programming Challenges: The Programming Contest Training Manual(book)
Excellent book, very useful. Use https://onlinejudge.org with it.
> https://www.youtube.com/playlist?list=PL07B3F10B48592010
Yeah, sure go ahead. Watch this course if you have time.
> Algorithms by Robert Sedgewick (book)
A great algorithms book but I prefer CLRS more mostly because CLRS is more math heavy and has pseudo code rather than Java examples.
> https://ocw.mit.edu/courses/electrical-engineering-and-computer-science/6-042j-mathematics-for-computer-science-fall-2010/ (course)
Though this is a good book some chapters aren't necessary at all. I suggest picking a good number theory book. AoPS, Briliant have good resources. I had used David Burton's Elementary Number Theory book and some parts of Computational Geometry by Berg et al.
Good luck!