I belive that all of these tools are very useful. I think that vim can be hard a little hard to usse for long periods of time but is perfect for writing things for your website. I think that markdown is much better to write with than HTML and is very helpful. I think that the git is not very hard to learn and I thiink that I understand it.
I think that these new techonolgys are not very hard to use and I am undersatnding how to use them pretty easily.
Some advice that I would give is just to practice in terminal and you should be able to understand it pretty quickly.