HELP! default theme won't change

[mythic]

I know this may have been answered already and I am sorry that I haven't found it if it has, however when I go through the admin center of the site with MAS installed, it does not change it. I have even switched the folders on my webhost and it still remains the same. I don't know what I am doing wrong or if there is something funky that I did during installation following the tutorial on this site, it was the stickied one.

Regardless besides deleting the files it always is using the elements theme upon going to the website. It is a nice theme but I would prefer either the one under default or even better to be able to install my own theme and actually use it. I know it is possible to do install themes so it should not be a big deal however, if it will not switch to a different theme for those coming to the site then I may not want to create a different theme.

Possible questions needing answered for questions:
Solution 1:
So in short, is it safe for me to edit the files in the elements theme?
If they are edited will they still work?
Solution 2:
How can I get it to use a different theme instead of that one?