"If a change from su to regular user in the terminal my path changes. Or if I change from regular used to su my path changes. The only way I can get my full path to come back is to start an other terminal session."
It is normal for root, su, and user to have different PATHs. You can change the PATH for user and root in .profile or .bashrc. I have never bothered to find where PATH is set for su. If you find out let me know.
To add directories to the path add the following command to /home/user/.bashrc
Be prepared. Create a LifeBoat CD.