With shadow-utils, it's very easy to create a safe working environment where you can't mess with tc files.
(present example uses the bash and shadow-utils extensions)
# In root create group, where <groupid> is your group name:
groupadd <groupid>.
# create user, where <userid> is your user name (you can use the same name as the group):
useradd -s /bin/bash -g <groupid> -d /path/home <userid>
# -s shell (I recommend using bash)
# -d setup a path to a home directory...it will create one if not already present.
sudo su - <userid>
# To add permissions, chown directories you want to use.
sudo chown <userid>:<groupid> /path
# To save beween boots, add to /opt/.filetool.lst:
etc/passwd
etc/group
# Also add your new home directory, if it's on the ramdisk.
# Tools for removing or modifying are in /usr/local/sbin
# examples:
userdel -r <userid>
usermod -d /newHome <userid>