These are the questions I can answer:
1) Change the login shell in the /etc/passwd file for the user to be the name of the script. When the script exits the shell will exit.
2) You can capture signals in a script like this. This one captures ^C or SigInt.
echo "Caught SigInt"
trap "SigInt 2" INT
# Start script here
3) Donno, try looking at tset. I know you can set bold text with it, don't think colors thought.
Yes, this is probably a programming post. Not much newbie content here.