The errors mean that your database host name, username, or password are incorrect. I would strongly suggest using our extensions to help you build your Connections and MySQLi code. Doing it by hand is time consuming and prone to errors.
Your connection file seems to have strings instead of variable references for all of the connection information. Did you do that on purpose? It isn't using the values you typed in above at all.
Also the values for a mysqli connection should be passed in the order: host, user, pass, database
you seem to have them in the order: host, database, user, password
There is also a random ! at the end of the password value that appears to be a typo. There are so many issues here it is hard to say where to start... I'd start by downloading the DataBridge v2 BETA and use that to recreate your connection and recordsets.