That poses severe risk. You should know the difference between SSH and FTP/SFTP. SSH will have access to many server operations which may impact your server. Providing SSH logins to general users are risky.
If you restrict the permissions level of ssh to block installation commands to the user and other security risks then you can. But this needs a good knowledge of linux administration in restricting what features/commands to the user ssh operations.
You are absolutely right. So I will use FTP/SFTP accounts.
After gave it a try I figured out following problem:
I can access the server by using FTP redentials using FTP.
But if I try to use same credentials for SFTP Connection it did not work.
Any hint how to solve it ?
(normal SSH connection works good. I changed the port from 22 to another port as recommended by firewall. I tried SFTP connection with this new set port. Connection can be establish, but the FTP credentials are not accepted.)