User frappe is the target user for easy install so no need to create it in advance. During CentOS7 O/S install you have the option to create a user i.e. admin with sudo access, the one that belongs to group wheel. After the O/S installation, work from that user to install the python script for bench.
$ sudo python install.py --production --user frappe
If you have change to view closely the bench installation, you can glimpse: TASK: SCREEN WALL. I think that is where this screen configuration was installed. But it is not a functional issue. I just don’t used to it.
The bench installation hangs towards the middle of the script. This is more bigger issue. That issue is related to nginx linux package not installed.
$ sudo yum install nginx
Restart bench python installation script. It successfully completes the installation for me. Yours may vary.